New Delhi, Jan 5 : The CBI on Monday told the Supreme Court that it will file a supplementary report on the citizenship of Congress MP from Assam, Mani Kumar Subba, whose nationality has come under a cloud after an initial probe revealed that he obtained his birth certificate in a fraudulent manner.

Additional Solicitor General Gopal Subramanium said there was a need to investigate what was stated in the affidavit filed by Subba on the issue of his nationality.

A Bench headed by Chief Justice K G Balakrishnan granted six weeks to the CBI to file the supplementary report.

Senior advocate Abhishek Manu Singhvi, appearing for the controversial MP from Tezpur, said three certificates have been procured from Nepal and it would be appropriate for the investigating agency to look into the matter.

The PIL filed by a Noida resident, Birendra Nath Singh, in 2005 had alleged that the Lok Sabha MP and lottery baron had come to India after a murder case was registered against him in Nepal in early 1970s.

His counsel Ambhoj Kumar Sinha contended that when the CBI had come to the conclusion that Subba has fraudulently obtained the birth certificate to establish his nationality he did not deserve any sympathy.

The Bench said the prayer for probe into the MPs citizenship was granted but it cannot unseat him from Parliament.

"This prayer for disqualification (as MP) cannot be granted," the Bench said adding that the procedure for disqualification can only be initiated according to the provision of Article 103 of the Constitution.

"You may go to President for appropriate remedy," the Bench said.