Tehran, Iran ? Iran acknowledged Saturday that some personnel at the country’s nuclear facilities were lured by promises of money to pass secrets to the West but insisted increased security and worker privileges have put a stop to the spying.

The stunning admission by Vice President Ali Akbar Salehi provides the clearest government confirmation that Iran has been fighting espionage at its nuclear facilities.

In recent weeks, Iran has announced the arrest of several nuclear spies and battled a computer worm that it says is part of a covert Western plot to derail its nuclear program. And in July, a nuclear scientist who Iran says was kidnapped by U.S. agents returned home in mysterious circumstances, with the U.S. saying he was a willing defector who was offered $5 million by the CIA but then changed his mind.

The United States and its allies have vigorously sought to slow Iran’s nuclear advances through U.N. and other sanctions out of suspicion that Tehran intends to use a civil program as cover for developing weapons. Iran denies any such aim and says it only wants to generate nuclear power.

Tehran said Saturday that it was ready to hold nuclear talks with the five permanent members of the U.N. Security Council — the U.S., Britain, France, Russia, China — as well as Germany in late October or early November. Foreign Minister Manouchehr Mottaki said the precise date was being discussed by the sides.

Iran’s semiofficial Fars news agency quoted Salehi as saying that some nuclear personnel had access to information about Iran’s plans for “foreign purchases and commercial affairs.” The report did not elaborate on the precise nature of the information or the timeframe over which the spying took place.

“Now, these routes have been blocked. The possibility of information leaking is almost impossible now,” Salehi was quoted as saying.