PARIS -- Investigators in three countries continued unraveling the plot behind a brazen $50 million diamond robbery in Belgium, focusing Thursday on a Swiss lawyer, a real estate businessman and a French luxury car exporter with a prison record for fraud.
After a series of raids on Tuesday and Wednesday in Switzerland, Belgium and France, the authorities started releasing some of the more than 30 men who were arrested and questioned in connection with the Feb. 18 robbery, in which armed men in police suits attacked a Zurich-bound plane minutes before takeoff from the Brussels airport.
Investigators in Belgium and Switzerland suspect that a critical organizer in the plot was Marc Bertoldi, 43, a French car exporter whose listed address was in a wealthy seaside neighborhood of Antibes on the Côte d'Azur and who owns a restaurant in Casablanca, Morocco. He was arrested Tuesday in France and remains in prison, awaiting a hearing May 16 in Metz for extradition to Belgium.
Investigators said that Mr. Bertoldi's arrival in Geneva after the theft provided a critical breakthrough in the inquiry. After Mr. Bertoldi's arrest, the police trailed an unidentified Swiss lawyer and a real estate owner on Wednesday as they made an exchange of a key to a cellar where some of the stolen diamonds were discovered.
Mr. Bertoldi's lawyer, Olivier Rondu, said on Thursday that his client denied the accusations against him and was willing to be extradited to Belgium to confront the charges.
"He has a surprising position that he wants to go to Belgium as quickly as possible to explain himself because he says he has done nothing," Mr. Rondu said. "He denies participating in the robbery at Brussels airport." Mr. Rondu also confirmed that his client had been convicted in the past for fraud and robbery and had served a prison term.
In Switzerland, where eight people were arrested on Wednesday, the real estate owner and the Swiss lawyer remained in detention. François Canonica, a lawyer for the Swiss lawyer, also denied any wrongdoing on his client's part, telling a Swiss newspaper, Tribune de Genève, "My client has faith that ultimately he will be acquitted."
This article originally appeared in The New York Times.