The CIA recruited a family of Swiss engineers to help it thwart the Libyan and Iranian nuclear programs as well as an underground network of Pakistani nuclear scientist Abdul Qadeer Khan, The New York Times reported Monday.

The newspaper said the operation involved Friedrich Tinner and his two sons, who have been accused in Switzerland of dealing with rogue nations seeking nuclear equipment and expertise.

The Swiss case against them has been hampered by the destruction of relevant documents, which Swiss officials have said was to prevent their falling into terrorist hands.

But the Times said the real reason for the destruction was pressure from the US Central Intelligence Agency, which feared that its ties with the Tinners would be exposed.

Over four years, the CIA paid the Tinners 10 million dollars, some of which was delivered to them in a suitcase stuffed with cash, the newspaper reported, citing unnamed officials.

In return the engineers delivered a flow of secret information that helped end Libya's nuclear weapons program, expose Iran's atomic efforts and undo Khan's nuclear supply network.

The Tinners also played an important role in a clandestine American operation to funnel sabotaged nuclear equipment to Libya and Iran, according to the Times.

Contacted by AFP, CIA spokesman Mark Mansfield declined to comment on the Tinner case, but noted that "the disruption of the AQ Khan network is a genuine and very significant intelligence success -- a success that has helped make the world a safer place."

Friedrich Tinner began working with Khan in the mid-1970s, using his expertise in vacuum technology to help Khan develop atomic centrifuges, the Times said.

But in 2000, the CIA recruited his son, Urs Tinner, who eventually persuaded his father and younger brother to join him as moles.

As part of their services, the Swiss engineers helped the CIA sabotage atomic gear bound for Libya and Iran, the report said.

In 2003 and 2004, inspectors from the International Atomic Energy Agency discovered vacuum pumps delivered to Iran and Libya that had been damaged cleverly so that they looked perfectly fine but failed to operate properly, according to The Times.

They traced the defective parts from Pfeiffer Vacuum in Germany to the Los Alamos National Laboratory in the US state of New Mexico.