WERE he alive, Konrad Kujau, the man who forged the Hitler diaries and countless paintings, would no doubt feel a tingle of pride for his great-niece, Petra.

She is being prosecuted for forging his signature on hundreds of cheap, Asian-made copies of works such as the Mona Lisa and selling them at an inflated price as “original Kujau fakes”.

Police in the eastern German city of Dresden have seized more than 200 “fake forgeries” in the offices of the art dealer and museum director. Petra Kujau, 47, faces fraud charges for selling at least 500 fake Kujaus to clients worldwide through an internet auction site for more than €550,000 (£381,000).

Some of the oil paintings, bought from art schools in Asia for as little as €10 apiece, fetched up to €3,500 because the Kujau signature inflated their value. The painter and military antiques dealer gained worldwide fame in 1983 for duping the magazine Stern and other publications, including The Times and Sunday Times, into serialising the Hitler diaries he claimed to have found.

Stern published extracts with the assertion that history would have to be rewritten. But two weeks later scientific tests on the paper and ink determined that the diaries were fakes. Kujau was jailed for three years for fraud.

He became a media celebrity in Germany after he served his term, appearing on chat shows and forging famous paintings and signatures. He never forgot to sign his work with his own name, however, to avoid prosecution.

He died of cancer in 2000 and is remembered as an entertaining maverick. “An expert examined the seized paintings and he said they weren’t of very high quality — not comparable with the good forgeries made by Konrad Kujau,” Marko Laske, a Dresden police spokesman, said. The confiscated works included fake Canalettos, Monets and some of the Dutch Masters.

Police were alerted by a tip-off from a former art student of Konrad Kujau’s, who noticed an inordinately large number of his paintings being offered in internet auctions.

The fraud has led to the closure of the Konrad Kujau Museum, which Petra set up in the southwestern town of Pfullendorf to exhibit her uncle’s copies of Picassos, Renoirs, Van Goghs and others.

“We felt we had to cancel the lease because of this,” Hans-Jürgen Rupp, the head of the Pfullendorf town council, said. “We’d known Frau Kujau for over a year and had a very good impression of her, so this has been a complete surprise. I don’t know now whether the paintings in the museum are real forgeries or fake ones — it’s hard for a layman to tell.”

The museum boasted a replica of the workshop in which Kujau diligently copied Hitler’s handwriting to pen such insightful gems as this diary entry dated 1936, before the Berlin Olympics: “Hope my stomach cramps don’t return during the Games.”

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game