Congress Party president Sonia Gandhi pledged Tuesday the Indian government would take action against anyone found to be involved in making money out of the UN oil-for-food program in Iraq.
The cabinet set up an inquiry last week into allegations in a UN report that former foreign minister Natwar Singh and the Congress benefited illegally from the program.
"If they are not innocent then action will be taken," Gandhi told a conference in New Delhi. "It made me extremely angry."
Singh resigned over the allegations in the report by former US Federal Reserve chairman Paul Volcker.
India's former chief judge R.S. Pathak will inquire into the naming of Singh as a beneficiary of four million barrels of Iraqi oil.
The Congress party, which heads the coalition government, was also listed as a beneficiary of a separate allotment of four million barrels.
"If these documents are authentic," Gandhi warned "... I shall clearly not protect" the guilty.
The Italian-born Gandhi, who also heads the ruling United Programme Alliance coalition, called for high ethical standards from India's political parties.
"We can no longer look the other way when such things take place," she said.
"There is a certain amount of cynicism about political parties. There is a feeling that we are all the same, that we are corrupt.
"It's important to do all we can to correct that impression."
Indian politics are regularly rocked by charges of corruption and Gandhi's late husband Rajiv faced allegations of kickbacks in a billion-dollar arms deal in 1986.
The Delhi High Court cleared him of wrongdoing in the affair last February, years after he was slain in 1991.
Singh remains in the cabinet as minister without portfolio and will return to his post as foreign minister if cleared.