Police recovered the violin, which has an insurance value of €1.5 million and is believed to date from 1721, along with other pieces from the stolen collection on Tuesday, according to a statement released on Wednesday.
Despite strong security at the home, the thieves broke past a high wall and a moat on October 17, 2008 to take, among other items, the valuable instrument made by Italian luthier Antonio Stradivari, widely lauded as the most significant artisan of his field.
Two suspects were arrested on Tuesday by commando police officers in Hannover, and a further two accomplices are under suspicion, a spokesman told news agency DDP. The men all come from the city, and were known by the police for other property thefts.
If accused in the gang robbery, all four men face up to ten years in prison if convicted.
Agents had long suspected the pieces might be found once the thieves sought money for the items, and were set on the trail to the accused after a man tipped them off eight weeks ago. Authorities then arranged a bogus transaction to locate the robbers, offering €500,000 for all of the stolen goods.
All of the booty from last October's theft was then recovered from a Volkswagen “Bulli” transporter van in Hannover-Linden.
The owners of the recovered items, the Bennigsen family, said they were “overjoyed” and “eternally grateful” for the return of the objects, a police statement said.
“It is fantastic that these articles, with such great historical value, have found their way back home,” head of the house, Baron Roderic von Bennigsen, told news agency AP.