US President Donald Trump promised to pardon WikiLeaks founder Julian Assange if he denied that Russia leaked emails of his 2016 election rival's campaign, a London court was told on Wednesday. Mr Assange's lawyer Jennifer Robinson said in a document that Mr Trump relayed the offer through former US Congressman Dana Rohrabacher, PA reported. The White House quickly issued a denial that President Trump had dangled a pardon in exchange for help in the Russia controversy, which has cast a shadow over his first term in office. "The president barely knows Dana Rohrabacher other than he's an ex-congressman. He's never spoken to him on this subject or almost any subject. It is a complete fabrication and a total lie," Mr Trump's press secretary Stephanie Grisham said in a statement. "This is probably another never-ending hoax and total lie" by the Democratic Party, she said, a day after Mr Trump controversially pardoned or issued other forms of clemency to 11 people including a former governor jailed for corruption, and other high-profile white-collar criminals. The revelation came at a case management hearing at Westminster Magistrates' Court before Monday's formal start of Washington's extradition request for Mr Assange to face espionage charges. If found guilty in the US, he could be jailed for 175 years. Mr Assange's defence quoted a statement from Ms Robinson in which she said that Mr Rohrabacher had been to see him. "On instructions from the president, he was offering a pardon or some other way out if Mr Assange said Russia had nothing to do with the Democratic National Committee leaks," she said District Judge Vanessa Baraitser ruled that the evidence was admissible. US intelligence agencies have concluded Russia hacked into the computer servers of the committee during Mr Trump's campaign against Democratic rival Hillary Clinton. WikiLeaks later published the emails, which proved politically damaging to Ms Clinton, before the November 2016 vote. Mr Assange, 48, is facing 18 counts in the US – all but one of them under the Espionage Act. None of them are related to the hacking. They concern WikiLeaks' publication of diplomatic and defence cables about US campaigns in Afghanistan and Iraq. Mr Trump has played down Russia's involvement in the Democrats leak, appearing to side with Russia over his own intelligence agency's assessment of what happened. "I have great confidence in my intelligence people, but I will tell you that President Putin was extremely strong and powerful in his denial today," he said during a joint press appearance with Russian President Vladimir Putin during their July 2018 summit in Helsinki. The extradition hearing is set to start at Woolwich Crown Court, which is next to the high-security Belmarsh prison where he is being held. The hearing is expected to last all week, before being adjourned for three months, to resume on May 18. Mr Assange appeared at the hearing by videolink, wearing dark tracksuit bottoms and a brown jumper over a white shirt. He spoke only to confirm his name and date of birth. He sat and held a pile of papers throughout the hearing.