CBI has told the Supreme Court it has evidence to prosecute Uttar Pradesh Chief Minister Mayawati in a disproportionate assets case as there is proof that she had amassed illegal wealth.

In an affidavit filed on Friday, the investigating agency said there is evidence to prove that the BSP chief and her family members acquired assets far exceeding their legal source of income.

The CBI said it has statement of witnesses to show that the UP chief minister forcibly acquired gifts from people.

Earlier, Mayawati had placed before the Supreme Court the records from a debate in Parliament to counter the allegations of CBI that there was ample evidence to prosecute her in the case.

CBI, in its affidavit filed in July 2009, said the competent authority has already taken a decision to file the final report under section 173 of the criminal procedure code in the designated trial court.

The agency had pointed out that her declared assets of Rs one crore in 2003 went up to Rs 50 crore in 2007 and said there was "ample evidence" to show she had amassed wealth disproportionate to her known sources of income.

Mayawati has claimed she had received the money through donations from party workers, which included meagre sums of Rs five and Rs ten which they contributed on her birthday.

The UP CM filed a petition in May 2008, seeking quashing of the criminal proceedings against her in the case alleging it was registered due to "political reasons".

The investigating agency had in July 2008, responded to the apex court notice saying there was sufficient evidence to show that Mayawati amassed wealth disproportionate to her known sources of income.

CBI alleged the assets shown by her in Akbarpur Parliamentary constituency were worth over Rs one crore whereas the assets increased to over Rs 50 crore in her declaration papers submitted during the 2007 assembly polls.

The agency had said she had been questioned about the wealth and Mayawati had claimed it came from donations of party workers.

However, the agency contended that Mayawati's reasoning was not plausible and that it was likely to file a chargesheet against her soon.

The agency refuted Mayawati's allegation that the UPA government was using the probe to serve its political interests.

CBI had registered the FIR against Mayawati on October 5, 2003, after the apex court had ordered the agency to probe into the Rs 175 crore Taj heritage corridor scam.

When the matter had come up for hearing earlier, the Centre had said the two reports placed before the apex court by CBI on September 18, 2003 contained the issue relating to the assets.

It had said Mayawati was participating in the inquiry since 2005, which could have been concluded by 2006 but has been delayed as the chief minister was making several representations -- even to the Prime Minister -- as she was "scared" of the investigation's outcome.