Disgraced Pakistani nuclear scientist A Q Khan has backed Iran's right to develop nuclear energy and said a propaganda campaign had been launched against that country's atomic programme.

In a damning revelation of Pakistan's nuclear proliferation, its disgraced scientist A Q Khan, the father of the country's nuke weapons programme, has admitted to the Pakistani nexus in the controversial atomic programme of Iran and North Korea, a media report said on Sunday.

A US lawmaker who introduced a legislation in the US Congress last week to pressure Pakistan to allow US officials access to its rogue scientist A Q Khan, asserted that his black nuclear market has not been closed down yet completely.

Two Japanese businessmen have disclosed details of secret trade deals they had with Pakistan's disgraced scientist A Q Khan, underscoring their "profit-first" business attitude that disregarded the threat of nuclear proliferation, the media in Tokyo reported on Tuesday.

In what could come as a major embarrassment to Japan's strident anti-nuclear stance, Japanese companies have been found to have played a key role in supplying at least 6,000 ring magnets and other materials to rogue Pakistani scientist A Q Khan.