The car manufacturer Audi has become the latest major German company to put its Nazi past on the table.

According to a new report, the firm — which has already paid millions of euros to a reparations fund — used 3,700 concentration camp inmates and 17,300 forced labourers on its wartime production line.

Titled The War Economy and Use of Labourers at Auto Union AG during World War II, the 520-page report was written by historians Martin Kukowski of the Audi firm and Rudolf Boch of the Technical University in Chemnitz.

The full extent of the company’s collaboration with the Nazis has never been revealed until now.

Company spokesperson Jürgen De Graeve said that the numbers are “much higher than we had thought. Older source material had put the number of forced labourers at 11,200 and the number of concentration camp inmates at 1,800.”

He said the company’s use of slaves began in the summer of 1942 and peaked in the final two years of the war.

Like many major German firms, including Siemens, Audi — then known as Auto Union — had a deal with the SS whereby workers would be provided.

The SS also built six labour camps for Auto Union forced labourers; they were satellites of the Flossenbürg Concentration camp, Mr De Graeve said. The labour camps were located at Leitmeritz, Zschopau, Zwickau, Siegmar/Hohenstein-Ernstthal, Oederann and Wilischthal.

In the past 20 years, several other German companies and government ministries have commissioned historians to research their Nazi-era history. The first was Volkswagen.