Libya bought plans to make a nuclear bomb from Pakistani scientists for "millions of pounds", Saif al-Isalm Gadaffi, son of Libyan leader Colonel Muammar Gadaffi, has admitted.

In an interview published in The Sunday Times Saif, 32, said his country had spent $40 million to acquire nuclear capability.

Some of the "five-star Libyan scientists" working on the bomb had trained in Britain, he claimed.

He confirmed that Libya had bought nuclear components, including centrifuges, from the black market. Some of the material came from Malaysia and various Asian countries, he said. Other components had been bought on the black market in South Africa.

"We dealt with an underground network of middlemen and secret workshops," he said. "This piece from here, that piece from there."

According to the report, revelations of the extent of Pakistani involvement will certainly increase American and British pressure on Pakistan President Pervez Musharraf, who is already accused of failing to prevent the illicit sale of nuclear material to Iran.

Pakistan admitted last week that "rogue scientists" might have peddled technology for "individual gain". It said several had been questioned, among them Abdul Qadeer Khan, regarded as the "father" of the country's nuclear bomb.

British and American experts who went to inspect Libyan weapons sites were taken aback when they found that nuclear scientists working for Gadaffi had what one western official described as a "full bomb dossier" from the Pakistanis.

Western officials said that the Pakistani scientists could have received from Libya as much as $100 million over several years, starting in the late 1990s.

They appeared to have been working on their own, without the knowledge of the authorities in Islamabad, the report said.

About Libya's decision to abandon its nuclear plans, Saif said he had worked as a "trouble shooter" in talks that alternated between London and Tripoli. "I was able to take messages to my father and explain to him. By the end we had a good relationship with the CIA, MI6 and all the Americans and British," he said.

His father needed reassurance, though, that they were not secretly pushing for "regime change".

"Once they assured us that they did not, everything went forward."

Saif said he now expected Libya to open up, with leading defence manufacturer BAE Systems and British Petroleum coming to the country for "big deals".

The report quoted a senior Arab source saying that some of the components for the Libyan nuclear programme were bought in Dubai and shipped to Libya. Dubai has hitherto been thought of as a transit point for illicit goods from Iran and other countries. This is the first time it has been accused of selling nuclear components, the report said.