Maintaining its attack against Mukesh Ambani and Reliance Industries, the AAP Thursday alleged that the UPA government had ignored a probe request against them three years ago despite an appeal made by the Indian mission in Singapore.

"The UPA government has not even bothered to investigate an open and shut case of huge money laundering done by Reliance and Mukesh Ambani," the party alleged in a statement -- a matter that has already been strongly refuted by the two parties.

"This is despite that fact that the Indian High Commission in Singapore had written to the central government as far back as Aug 31, 2011 requesting such an investigation," said the statement, released by party leader and senior lawyer Prashant Bhushan.

The party alleged that Rs.6,530 crore had been invested in some of the group companies of Reliance Industries by a company in Singapore, which, it added, not only claims to be a small firm but also has no office, no equity and files no tax returns in that country.

"The high commission had stated that all this money has gone into Reliance (Industries) group of companies in India with the major chunk going to Reliance Gas Transportation Infrastructure Ltd, which is a company 100 percent owned by Mukesh Ambani personally."

The Singapore company has since closed, the party said, and sought to name its owner.

Since such allegations had been made earlier, Reliance Industries had issued a statement a couple of days ago denying any wrong-doing either by the company or its chairman Mukesh Ambani.

"As stated earlier, it is being reiterated that neither Reliance Industries nor Mukesh Ambani have or had any illegitimate accounts anywhere in the world," said the statement issued Tuesday.

"RIL has business interests in several countries with turnover of thousands of crore in rupees. As a part of their normal business, these international subsidiaries of RIL deal with several global banks," the statement said.

"These accounts are fully compliant with all regulations and are disclosed in their appropriate jurisdictions and in India."