Wikileaks founder Julian Assange was back in a London courtroom Tuesday, arguing against his extradition to Sweden on sexual assault allegations. Assange's lawyers claim the allegations against him aren't extradition offenses and returning him to Sweden would abuse his human rights, the BBC reported. Assange has denied the allegations and maintained the case was politically motivated because his Web site leaked hundreds of thousands of sensitive U.S. military and diplomatic documents. The four allegations against Assange are improperly described in the arrest warrant, attorney Ben Emmerson said, noting only one would be considered a crime in England, The Guardian reported in its live blog of the proceedings. The defense also argues sex between Assange and the two Swedish women who accused him of rape was consensual. Besides arguing that the allegations in the extradition order against Assange aren't crimes in England, Emmerson said the order also was flawed because it seeks Assange's return to Sweden "not for prosecution but for the purposes of an investigation." Assange hasn't been formally charged with any offense. Under the Swedish legal system, charges would be filed after extradition and a second round of questioning. Emmerson said using extradition only for an investigation amounts to "a disproportionate utilization" of the European arrest warrant system. The accusations against Assange concern a trip the Australian made to Stockholm last August. The Swedish authorities secured a European arrest warrant in December, after which Assange was arrested and released on a heavily conditioned bail agreement.