By TOM HAYSNEW YORK (AP) â¿¿ While the FBI eavesdropped on Frederic Cilins this year, prosecutors say the Frenchman sometimes dropped his voice to an urgent whisper. They also say his words, though quiet, spoke volumes about a criminal case full of international intrigue. "You must destroy everything, everything, everything," Cilins allegedly instructed the wife of a deceased president of Guinea now living in Jacksonville, Fla. The secretly recorded conversation is recounted in filings in federal court in Manhattan that detailed for the first time how, in the midst of an ongoing grand jury investigation, the FBI began tracking Cilins and his role as a globe-trotting emissary for wealthy Israeli mining magnate Beny Steinmetz. Cilins, who was arrested in Jacksonville in April, has pleaded not guilty to U.S. charges that he was dispatched to Florida to convince the president's widow to destroy paperwork in her possession that, if made public, would expose how Beny Steinmetz Global Resources bribed officials in the impoverished West African nation to gain iron ore rights that the company turned into a multibillion-dollar windfall. The Guernsey-based BSGR â¿¿ billed on its website as a "diversified natural resource business" that employs 6,000 people on four continents â¿¿ has vehemently denied any wrongdoing. The company "has never paid any money as bribes or blackmail," it said in a statement from its London office. It added: "We have no reason to believe that Mr Steinmetz is under investigation in the US or elsewhere. Mr Steinmetz is a hugely respected businessman who has operated in dozens of countries for 35 years and has faced no evidenced allegations anywhere." An FBI spokesman in New York declined to comment. The controversy over the mining rights began in 2010, when current Guinea President Alpha Conde took office and began trying to undo a deal made by a previous administration with a reputation for corruption. BSGR has pushed back, claiming the project was legitimate.