Barring of the two Bhabha Atomic Research Centre officials - Dipankar Mukherjee and Mohd Afzal - is revealed in documents held by a Melbourne-based company GBC Scientific that has been involved in a dispute with the government over its equipments export, which Australian officials claim can be used in nuclear weapons programme, The Age reported.

Documents disclosed that the two officials were refused short-stay business visas in April to finalise the purchase of an X-ray machine from GBC's laboratory though the machine was not subject to any export controls.

However, in a letter to GBC, Australian Immigration Department refused to divulge reasons for denying visas to the Indian officials and stressed the importance of applicants meeting "Australia's health and character standards".

"As part of visa processing, various checks must be undertaken prior to visa grant. This includes mandatory health checks, character and security checking for privacy reasons, I am unable to discuss the reasons why Mukherjee and Afzal's visa applications were refused," the department's acting assistant secretary, Michael Clisby, wrote.

Another letter written on behalf of the then Foreign Affairs Minister Alexander Downer argued that the two worked for an organisation that played "a leading role in India's nuclear weapons research".

"Knowledge the individuals could acquire in Australia would be of assistance to India's WMD programme," Assistant Secretary for arms control and counter proliferation John Sullivan said.

The episode occurred as the previous John Howard government was negotiating a deal to export uranium to India.

The current Kevin Rudd government has ruled out any such deal with New Delhi which has not signed the Nuclear Non-proliferation Treaty (NPT).

GBC Scientific managing director Ron Grey criticised the decision as "hypocritical" as authorities had barred his Indian customers while it was negotiating to sell uranium to India outside the NPT.