NEW YORK, Jan 17: The US law enforcement officials said on Friday that they were looking into whether the Pakistani government was involved in a plot by a South African businessman, an Israeli national , to export trigger devices that could be used for nuclear weapons, The New York Times reported on Saturday.

"That's one possibility that we're investigating," said an official, on condition of anonymity.

"We know these devices went to Pakistan. What we're still investigating is where exactly they ended up and who was behind it."

Asher Karni, an Israeli who lives in South Africa, was arrested in Denver earlier this month on charges that he had illegally exported the devices to Pakistan without a license. In court documents, the American authorities charge that Mr Karni, 50, was at the centre of a global operation that used front companies and false billing records to route the trigger devices from a private manufacturer in Salem, Mass., to South Africa, the United Arab Emirates and ultimately Pakistan, the paper said.

The devices, high-speed electrical switches called triggered spark gaps, are typically used in hospitals to break apart kidney stones. But hospitals usually keep only a few on hand "not the 200 that Karni is accused of ordering from an American supplier, Perkin-Elmer Optoelectronics, of Salem."

A Pakistani diplomat in Washington was quoted by the paper as saying Pakistan would cooperate in the investigation, and that it had no knowledge of the plot that the US officials had outlined.

The US officials said they had come to focus on the possibility that the Pakistani government was involved for several reasons, beginning with the large number of devices that Mr Karni ordered.