Leuchter Report on Mauthausen Gas Chamber

The Leuchter Report on the Mauthausen and Hartheim Castle gas chambers is included here solely for the purpose of describing these facilities in detail.

The report was written by Fred A. Leuchter, Jr. after visits to Mauthausen and Hartheim Castle in April 1989. Leuchter had been commissioned to do this report in connection with his testimony as an expert witness for the defense in a criminal case in Canada in which a Holocaust denier, Ernst Zündel, was charged with "spreading false news" when he published a booklet entitled "Did Six Million Really Die?"

Leuchter has been thoroughly discredited as a gas chamber expert; the judge at the Zündel trial noted that Leuchter has no degree in Engineering and he has "no expertise" about gas chambers. Leuchter no longer works as a gas chamber consultant.

Photos of the Mauthausen Gas Chamber

The Leuchter Report is quoted verbatim below:


The alleged gas chamber at Mauthausen Concentration Camp was located between the hospital, the crematory and the jail. Like Dachau, it is generally considered by some established historians and the Revisionists to have never been utilized for executions.

The alleged gas chamber has an area of some 150 square feet and a volume of 1,164 cubic feet. It has a ceiling height of some 7.8 feet containing piping and working shower heads. It has a floor drain of some eight (8) inches by eight (8) inches and steam pipes on the north-west wall for heating. The walls are finished in ceramic tile. It has two doors and provision for gasketing as do many European doors. It has an alleged gas vent in the ceiling of the north wall but the purpose of this alleged gas vent cannot be verified since the ground above has been repaved. Additionally, an adjacent room is alleged to have been a control room for inletting gas (apparently not solid "Zyklon B" but actual hydrogen cyanide gas). There is no hardware in place for this function nor is there any evidence of its removal. The museum officials are very confused and incoherent about the operating function and offered a succession of varying explanations on how the gas was introduced into the chamber. It has been stated by museum officials that the gas was introduced: (1) through overhead shower heads; (2) through a shaft in a remote corner of the room; and (3) through a perforated pipe, which does not exist today. The lighting is not explosion proof but merely water resistant. There is nothing to indicate the alleged control room ever existed. The facility is entirely underground, as is the morgue, the hospital and the jail. The facility also housed the area for the condemned prisoners where they were executed by shooting.

It appears from the construction that this facility was constructed as, and further was utilized only as, a shower room. The installation has no provision to prevent gas leakage, the lighting is not explosion proof, the floor drain would allow leakage into the sewer system and there is no provision for inletting gas or for exhausting the air gas mixture after an execution. Further, there are steam heating pipes (radiator) on the northwest wall of the chamber, which would most likely result in an explosion if hydrogen cyanide gas were deposited in the room. Additionally, all shower heads are working and the overall design is unquestionably that of a shower room.

-Forensic Considerations at Mauthausen-

Four (4) forensic samples were selectively removed from the alleged gas chamber at Mauthausen and returned to the United States for chemical testing. Detailed analysis was completed on each sample for both iron and cyanide in accordance with the standard procedures utilized in the prior testing of samples from Auschwitz I and Birkenau. Resultant to this testing and comparison with known test results for insoluble iron cyanide compounds, it is demonstrated that this alleged gas chamber facility has never been exposed to repetitive concentrations of cyanide necessary for execution: referencing the delousing chamber control sample #32 (from Birkenau) as having 1050 mg/kg, the greatest concentration found at Mauthausen was 32 mg/kg, indicating fumigation of the building at some point in its history. This clearly indicates that this facility was not a gas chamber.

Resultant to an indepth investigation of this installation, this investigator has determined that this facility was not capable of conducting executions by gas. In the best engineering opinion of this investigator this facility could never have supported gas executions and was never utilized as a gas execution chamber.

Adjacent to this facility is the morgue area, which contains a refrigeration unit for cooling the cadavers. This morgue also contains a dissection room and a crematory, all adjacent and connected to the hospital. The existing crematory contains a furnace with one (1) retort. In an adjacent room, there are indications of another crematory furnace of one (1) retort which has been removed. This existing retort shows signs of considerable use, which is expected in a camp of this size with only two (2) retorts. Both units were coal fired.

For the record the alleged gas chamber would have held only seventeen (17) persons, utilizing the nine (9) square foot rule. Without an exhaust system, this investigator estimates that it would require at least a week to vent for the same reasons as explained for Dachau.

Photos of Hartheim Castle

-Hartheim Castle-

This facility consists of a masonry room adjacent to a tower of a centuries old castle. This castle was donated by the monarchy to the mental health service of Austria and was later placed under the control of the German Government when it acquired control of the Austrian Government and the mental health service. The facility had been utilized as a mental hospital and under German control it continued as such. Allegedly, mass gas executions were conducted at this location on prisoners transferred from Dachau and Mauthausen for this purpose.

The alleged gas chamber was a lower level room adjacent to one of the castle towers. This room has an area of 192 square feet and a volume of 1,728 cubic feet. It has a vaulted ceiling of some 8.9 feet at the highest point. The installation had one (1) door and one (1) window, although a rectangular aperture has now been made into an adjacent room. There are no facilities to inlet "Zyklon B" or evacuate the gas after use. The room now has been completely remodeled. It has recently plastered walls and ceiling. There are three (3) new floor surfaces, one on top of the other. Even the door has been changed to a modern conventional mental institution cell door with a shuttered view port. The window is alleged to have been original, but would leak gas if used for this purpose. Neither the door nor the window has any provision for gasketing. Allegedly, all gassing apparatus was removed by January, 1945. In truth, there was no gassing equipment in that the walls are very thick as characteristic of castle architecture and construction and not easily cut to accommodate the installation of gas vents or gas inlet ports. It and the adjacent room contain memorial plaques to those who allegedly died in gassings here. The castle is presently used as an apartment building.

It appears by construction that this facility would not lend itself for use as a gas execution installation, the walls being too thick for the installation of gassing equipment. Certainly, because of the construction, any changes would be visible, and not easy to conceal. There is no provision for a gas stack for evacuation of the gas-air mixture and no way to install one. The window would certainly leak, allowing large volumes of deadly gas to escape. No samples were taken at this location because of the extensive remodeling to the facility which decidedly would obscure any test results.

For the record, the alleged gas chamber would have held only some 24 persons, utilizing the nine (9) square foot rule. Without an exhaust system this room would require at least one week to vent (refer to Dachau).

Resultant to an indepth investigation of this installation, this investigator categorically states that in his best engineering opinion this facility was not ever utilized for, and could never have supported gas executions. The actual use of this room is unknown to the investigator. Based on a comparison with its mirror image on the other side of the facility, it could have been a store room.

There are no crematoria extant at this location.

It is perplexing to note that the official museum literature states that Dachau and Mauthausen, both having facilities equal to, or better than those at Hartheim Castle, sent inmates to Hartheim for gassing. It is unclear why this should occur since Hartheim's alleged facility would have been so difficult to construct, was so small and so distant from Dachau (200km). Based on all the available evidence it becomes abundantly clear that no gassing facilities ever existed at any of these locations.

Specialized Hardware: Non-existence

In all the author's investigations in Poland, Germany and Austria, hardware or construction remarkable to gas chambers has never been found. There are no forty (40) foot stacks, no ventilators, no gas generators, no intake air preheaters, no special paint or sealants on walls, floors or ceilings, no safety devices for the operators, and no coherent design consistently utilized throughout the alleged gas chambers. It is inconceivable that the Germans, having the highly developed technology utilized on the delousing chambers, would never have applied this technology to the alleged execution gas chambers.


After reviewing all the material and inspecting all of the sites at Dachau, Mauthausen and Hartheim Castle, this investigator has determined that there were no gas execution chambers at any of these locations. It is the best engineering opinion of this investigator that the alleged gas chambers at the above inspected sites could not have then been, or now be, utilized or seriously considered to function as execution gas chambers.

Prepared this 15th day of June, 1989 at Malden, Massachusetts.

Fred A. Leuchter Associates, Inc.
Fred A. Leuchter, Jr.

* * *

End of Report



This page was last updated on July 9, 2009