India’s prime minister denied Friday any involvement in or knowledge of a bribery scandal arising from U.S. diplomatic cables obtained by WikiLeaks and published in the Indian media, and he questioned the cables’ credibility.

“The government cannot confirm the veracity, content or even existence of the cables,” Prime Minister Manmohan Singh said. “The government rejects the allegations firmly. It is unfortunate that the opposition continues to raise old charges.” Reading a brief written statement in parliament, he said no one in either the ruling Congress Party or his government “has engaged in unlawful activity.”

In the diplomatic cable published in the newspaper the Hindu on Thursday, a U.S. Embassy official, Steven White, wrote that a Congress Party aide showed him cash set aside for bribing lawmakers during a key vote in parliament after a debate on the controversial civilian nuclear agreement between India and the United States.

Singh described the content of the cable as “speculative, unverified and unverifiable,” and accused the opposition leaders of giving an “unverified communication a dignity.”

But the whistleblower Web site WikiLeaks cable continued to hamstring Indian parliament for the second day. Opposition members shouted slogans against Singh’s government soon after his statement, and the House was adjourned.

A series of corruption scandals in recent months has dogged Singh’s government, implicating several members of his government and the Congress Party.

At an earlier conference in New Delhi on Friday, Singh said he was not aware of any bribery and had not authorized anyone to purchase any vote in parliament.

But Singh admitted that the corruption charges “do affect us, do affect our image, both at home and abroad.”

On Friday the Hindu newspaper published a fresh set of cables that Secretary of State Hillary Rodham Clinton sent to the employees of the U.S. Embassy in New Delhi asking about political and business leanings of key ministers in Singh’s government.

The leaks have added to the growing perception that Singh’s government is toeing the American line on matters related to appointments and foreign policy. Indian news television networks conducted extensive discussions on Thursday and Friday about the deepening American influence on Singh’s government.

“I want to know whether India’s control room is in Delhi or Washington,” Gurudas Dasgupta, a member of the Communist Party of India, said in parliament.