ISLAMABAD, Pakistan — The architect of Pakistan’s nuclear program yesterday rejected a report alleging that his network may have shared blueprints for an advanced nuclear weapon with countries such as Iran and North Korea.

Speaking to the Associated Press by telephone, Abdul Qadeer Khan described the report issued Monday as a “pack of lies” and lashed out at its author, a former top U.N. arms inspector, David Albright.

“It is all concoction, it is a pack of lies, and this is a campaign. Whenever they see Pakistan can be pressured, they pressure it,” Mr. Khan said from the Islamabad villa where he is under house arrest. “The previous government has been succumbing to such pressure.”

The 72-year-old Khan is a hero in the eyes of many Pakistanis for his pivotal role in developing the Islamic nation’s nuclear bomb. He was detained in December 2003, however, and admitted in early 2004 that he operated a network that spread nuclear weapons technology to Iran, North Korea, and Libya.

Khan has opened up to the media since Pakistan’s new civilian government took power this year, eclipsing the dominance of President Musharraf.

The scientist has been strongly critical of Mr. Musharraf, a former general who pardoned Mr. Khan but ordered his detention after America and the U.N. nuclear watchdog presented Pakistan with evidence of his proliferation activities. The government, however, has refused to let outsiders such as the International Atomic Energy Agency directly question him.

Mr. Khan made a rare trip out of his home in May, when he was allowed to visit the Academy of Sciences in the capital, Islamabad, to express condolences over the death of a former colleague.

Unanswered questions remain about the technology that Mr. Khan’s network shared with nations such as North Korea and Iran, and whether Pakistani authorities knew what he was doing or profited from sales.

Mr. Khan’s network was largely dismantled in 2004 and in the investigation of its operations Swiss officials seized computers and files from three brothers accused of smuggling for the network. By 2006 the files had been deciphered and among them was a detailed design for an advanced but small nuclear warhead.

Mr. Albright told the Associated Press on Monday that the design goes far beyond the schematics and information about nuclear weapons available on the Internet.