Clinton campaign currently trying to highlight fears Vladimir Putin's Russia is influencing election in favor of Donald Trump

tells Daily Mail Online it is seeking interview with him - and lobby group Citizens United says he should get immunity

A Chinese billionaire at the center of a 20-year-old Clinton foreign donor scandal is being called in to answer questions from Congress about his role in the influence-buying scheme, in a move that could revive yet another Clinton controversy from the 1990s.

The House Oversight Committee told Daily Mail Online that it will seek an interview with Ng Lap Seng, 68, who evaded congressional investigators for years.

He has now re-appeared in the United States and is being held in New York on unrelated bribery charges.

One campaign group is even suggesting that Congress grant him immunity from the charges in return for testifying.

Ng, a Macau businessman with ties to the Chinese government, was accused of funneling over $1 million in illegal foreign donations to support Bill Clinton's reelection campaign in 1996.

Finally facing questions: Billionaire Ng Lap Seng, who was in Federal Court in Manhattan in June, fled the country to avoid giving Congressional testimony but is now facing demands to give evidence

Key campaign: Bill and Hillary Clinton campaigned as a couple in 1996. But the campaign faced investigation over whether Chinese Communists attempted to influence the outcome of the election

At the time, Ng declined to come to the U.S. to cooperate with congressional investigators in the case, which became a sweeping national scandal and raised suspicions about Chinese government efforts to influence the U.S. election.

According to congressional investigators, Ng laundered the illegal campaign donations through a close Clinton associate in Arkansas named Charlie Trie during the 1996 election.

Trie, who sent the donations to the Democratic National Committee and Clinton's legal defense fund, pleaded guilty to violating campaign finance laws in 1999.

The House Oversight Committee said it will take the opportunity to finally question Ng about the foreign donation scheme now that he is under house detention at a $3 million Manhattan apartment, awaiting trial on separate charges that he tried to bribe a top UN official.

'We plan to request an interview,' said a spokesperson for the committee.

Then Republican senator Fred Thompson chaired the committee and said that it found that China's Communist government was involved in a plan 'to pour illegal money into American political campaigns' in an effort to 'subvert our election process', the Washington Post reported.

However, other lawmakers, including Sen. Joe Lieberman, then a Democrat, said there was not convincing evidence that China was directly involved in the funding.

Ng's attorney, Hugh Hu Mo, who has also represented Chinese government entities, said he would oppose any efforts by Congress to question his client.

The House Oversight Committee could potentially override this by issuing a subpoena for Ng's testimony.

The timing could be a blow to the Clinton campaign, reigniting a decades old foreign corruption scandal just as Hillary Clinton has secured the Democratic presidential nomination.

The Clinton Foundation has previously faced scrutiny for accepting millions from foreign governments while Hillary Clinton was secretary of state.

The House Oversight Committee's move comes on the heels of a letter from the watchdog group Citizens United, which asked Ng's attorney to make him available for interviews with congress.

Testimony: In an investigation led by then Senator Fred Thompson, the Chinese government was accused of trying to affect the 1996 election outcome. Charlie Trie, who was jailed, later gave evidence.

Foreign meddling: Democrats have this week raised the possibility that Vladimir Putin (right) is trying to influence the outcome of this election in favor of Donald Trump (left), who denies such a claim.

Finding: Then Republican senator Fred Thompson chaired the government oversight committee and said that it found that China's Communist government was involved in a plan 'to pour illegal money into American political campaigns' in an effort to 'subvert our election process''

David Bossie, president of Citizens United, was the former chief investigator for the House Oversight Committee during the foreign donor probe in the late 1990s.

He said in a letter to Ng's attorney on Wednesday that the committee had obtained substantial evidence of Ng's involvement in the donation scheme.

'Although Mr. Ng did not cooperate, the Committee's investigation uncovered substantial information about financial transactions involving your client that appear to have been aimed at influencing the outcome of the 1996 presidential election in favor of Bill Clinton,' wrote Bossie.

Bossie said that now that Ng is under house arrest in New York, 'I ask that you consider making him available for an interview with Congress to answer questions about his alleged role in influencing the 1996 presidential election.'

The letter, which was copied to House Oversight Committee chairman Jason Chaffetz and Senate Judiciary Committee chairman Charles Grassley, also suggested that Congress could grant immunity on the pending bribery charges to Ng 'in exchange for his critical testimony concerning the alleged foreign influence of our nation's sacred presidential election process'.

A spokesperson for the committee did not say whether it would consider this option.

Citizens United say that such a deal is legally possible.

Ng was arrested in New York last year and charged with bringing suitcases of cash into the U.S. to bribe officials, including the former president of the UN general assembly. Prosecutors say the scheme also involved Chinese government officials.

John Ashe, 61, the former president of the UN general assembly accused of accepting the bribes from Ng, was killed by a barbell weight while working out last month. He was also under investigation at the time.

In 1997, investigators on the Senate Government Affairs committee said they found evidence linking the Communist Chinese government to the foreign donation scheme.

The issue of foreign meddling in US elections has been in the spotlight in recent days, with the Clinton campaign trying to link Donald Trump to the Russian government's suspected role in the recent hack of internal DNC emails.

But the Ng case shows that allegations of foreign influence in presidential campaigns is not new, and that outside governments have long been suspected of working to sway outcomes and purchase political influence.