WASHINGTON: Nader Modanlo was facing five more years in federal prison when he got an extraordinary offer: US President Barack Obama was ready to commute his sentence as part of this month's historic and then still-secret prisoner swap with Iran. He said no. To sweeten the deal, the US administration then dropped a claim against the Iran-born aerospace engineer for $10 million that a Maryland jury found he had taken as an illegal payment from Iran, according to interviews with Modanlo, lawyers involved and US officials with knowledge of the matter. The surrender of the US claim, which has not previously been reported, could add to scrutiny of how the Obama administration clinched a prisoner deal that has drawn criticism from Republican presidential candidates and lawmakers. A Washington-based spokesman for the Justice Department declined to comment on discussions over the $10 million, which the jury found that Modanlo was paid to help Iran launch its first satellite in 2005. Modanlo says the money was a loan from a Swiss company for a telecoms deal. In the prisoner swap, five Americans held in Iran were released at the same time as seven Iranians charged or imprisoned in the United States were granted pardons or had their sentences commuted. The deal accompanied the Jan. 16 implementation of a landmark agreement that curbs Iran's nuclear programme in exchange for sanctions relief. Even after receiving the improved offer on Friday, January 15, Modanlo said he didn't budge at first. He wanted a chance to clear his name in court, he says. 'I was mostly disappointed that I have to give up my right to appeal,' Modanlo, 55, told Reuters in one of his first interviews since being released. 'If they believe in their justice system why would they deprive me of it? Let them prove me wrong.' As part of their clemency agreements, all of the Iranians had to renounce any claims against the US government. All but one had been accused of violating the economic sanctions the United States has enforced against Iran for decades. Modanlo's reluctance to accept Obama's offer became an eleventh-hour complication to an otherwise carefully staged deal with Iran that had been negotiated in secret for months by US Secretary of State John Kerry and his Iranian counterpart. He only agreed to accept the clemency offer on Saturday, January 16 as the clock ticked toward what US officials said was the final deadline, according to Modanlo and US officials. He was freed the next day from a federal prison near Richmond, Virginia. The release marked an abrupt conclusion to his case after a sprawling, decade-long investigation into Modanlo's role in brokering Iran's access to space technology. US federal agents had pursued evidence from the suburbs of Washington to Switzerland and Russia. Modanlo was serving the longest sentence of any of the seven Iranians and had the most extensive, established connections to Iran's government. He was also the only one known to have initially declined Obama's offer, according to interviews with lawyers for the men. An official at Iran's interests section in Washington, Iran's de facto embassy, testified in Modanlo's defense at his 2013 trial. The same Iranian representative, Fariborz Jahansoozan, was instrumental in brokering the prisoner exchange in recent months, lawyers for those involved have said. 'This story is done and over with,' Jahansoozan said when reached by Reuters, declining to discuss the case in detail. 'Please let it go and move forward.' After two years in prison, Modanlo says he is finding that hard. 'I know this cloud is going to be over my head forever,' he said.