US authorities on Monday announced covert lobbying and arms dealing charges against a US-Israeli analyst who has accused President Joe Biden's son of corruption.

Federal prosecutors in New York charged Gal Luft, the head of a think tank outside the US capital, of engaging "in multiple, serious, criminal schemes," according to a Justice Department statement.

Luft has leveled allegations of corruption against the family of Biden, and Republican politicians called the charges against Luft an attempt to intimidate a key witness.

According to prosecutors, Luft "subverted foreign agent registration laws in the United States to seek to promote Chinese policies by acting through a former high-ranking US Government official."

Furthermore, Luft "acted as a broker in deals for dangerous weapons and Iranian oil; and he told multiple lies about his crimes to law enforcement," the statement said.

Luft was arrested in February in Cyprus on US charges, but fled after  he was released on bail awaiting extradition proceedings, prosecutors said. Luft remains at large and the Justice Department is asking for information on his whereabouts.

In a video published by the New York Post last week, Luft said that in 2019 he provided evidence to US Justice Department and FBI officials on what he said were Biden family financial transactions with the Chinese energy conglomerate CEFC.

Republican Senator Ron Johnson accused the government of a coverup.

"He's got a wealth of information. But they never followed up on that meeting," Johnson said recently on Fox News. "Instead, they arrested him in Cyprus to silence him."

With Biden ramping up his bid for a second term as president in the 2024 election, in May Republicans in Congress accused the Biden family of pocketing more than $10 million from dealings with Chinese and Romanian firms -- though they offered little evidence.

These accusations are part of a long-running campaign targeting Hunter Biden, the president's son and only surviving child of his first marriage.

Republicans accuse Hunter Biden of capitalizing on his father's influence when he served as vice President under Barack Obama in order to engage in shady dealings in several countries.