Police nab man claiming to sell back Picasso, Monets stolen in $100 million heist AFP / Getty Images A space left empty at the Kunsthal museum in Rotterdam, Netherlands on Oct. 16, 2012 after theives stole a painting by French artist Henri Matisse and six other masterpieces worth up to $130 million. By David Rising and Toby Sterling , The Associated Press AMSTERDAM - German prosecutors said Thursday they arrested a man after he allegedly tried to sell seven paintings taken in a Netherlands heist, including a Picasso and two Monets, back to their Dutch owner. The 46-year-old German is suspected of blackmail for allegedly offering to broker the return of the paintings to the Triton Foundation, a collection of avant-garde art. The seven paintings, which also included a Matisse and a Gauguin, were grabbed in the early hours of Oct. 16 in a lightning theft from the Kunsthal gallery in Rotterdam where they were on display. The paintings, worth tens of millions of dollars, have not been recovered. Cologne's head prosecutor Ulrich Bremer, told The Associated Press that the man was arrested on a warrant from his office on Wednesday near the city of Freiburg in southwestern Germany. He would not release the man's name. Three Romanian men suspected of carrying out the heist were arrested Jan. 22 in Bucharest and remain in custody there. A 19-year-old Romanian woman was arrested in Rotterdam on March 4 on suspicion of assisting the thieves. Police believe the works were brought shortly after the theft to a home in Rotterdam where the young woman was staying and removed from their frames. Rotterdam prosecution spokeswoman Babeth Knol confirmed Thursday that Dutch prosecutors are working with German and Romanian police in the case, but could not comment further. The Triton Foundation collection was put together by multimillionaire Willem Cordia, an investor and businessman, and his wife, Marijke Cordia-Van der Laan. Willem Cordia died in 2011. Experts on stolen art such as Britain's Art Loss Register say that thieves often don't understand how difficult it is to sell easily identifiable paintings by famous artists. After thieves are unable to dispose of them for anything resembling their value at auction, they frequently attempt to ransom them back to their owners. But Bremer said there were still a lot of questions surrounding the German suspect - including whether he might be a scam artist with no connection to the paintings. "He said he had access to the paintings but whether he was really part of the theft ring or had contact to them and to the paintings, or whether he was some sort of a free-rider, is part of our investigation," Bremer said. Bremer said his office was involved because the suspect had contact with two lawyers in the Cologne area - both by telephone and in person. Both were "involved in offering the return of the paintings" but neither have been arrested. "What role the two attorneys played is part of the investigation," he said. Dutch national broadcaster NOS news reported that representatives of the Triton Foundation had met with the lawyers in late 2012, then notified the police. Bremer said the suspect will be transferred to Cologne within several days. He said his office had been investigating the case since November 2012.