Mr Galloway has been accused of profiting from Iraq’s now defunct oil-for-food programme in documents released by the US Senate Homeland Security and Government Affairs subcommittee.
The outspoken left-wing politician struck back at claims he illegally gained the rights to export 20 million barrels of oil from Saddam Hussein’s government.
He claimed that US President George W Bush and British Prime Minister Tony Blair were the ‘true villains’.
“The people who stole Iraq’s oil and wealth are George W Bush and Tony Blair and the puppet government in Baghdad,” Mr Galloway said.
“I have never seen a barrel of oil, I have never owned a barrel of oil, I have never bought one, I have never sold one and neither has anyone else on my behalf,” Mr Galloway told a rally of his anti-war party, Respect, in central London.
Buoyed by the enthusiastic mood of his reception, the maverick MP said he had also broken a US trade sanction during his visit.
“I did a bit of sanctions busting in Washington yesterday, I smoked a Havana cigar (…) I smoked it inside the Capitol building and I even blew the smoke at the White House,” he said, shouting above the thunderous applause of his supporters.
“And I think we blew them away, didn’t you?”
Mr Galloway was dumped by Tony Blair’s Labour Party in 2003, going on to win a parliamentary seat in east London.
That same year, Britain’s charity watchdog began investigating the Mariam Appeal, a non-profit group set up by Mr Galloway in 1998 to provide medical aid to Iraqi civilians.
The Charity Commission found last year that no funds had been misused or acquired from improper sources, according to the Agence France Presse news service.
The findings formed the basis for Mr Galloway’s fiery defence before the US Senate committee.
But, the head of the Charity Commission now says a fresh inquiry is possible, if new information is produced by the US investigation.
Kenneth Dibble reportedly said that there had been ‘limitations’ to its inquiry, due to a lack of records.