The prosecutor is also asking to conduct a DNA test.
Assange has been stuck inside the South American country's London embassy since June 2012 to avoid a British extradition to Sweden. Sweden wants to question him on allegations of sexual assault and rape, which he denies.
The Australian says he fears that if Britain extradited him to Sweden he would then be extradited to the United States where he could be tried for one of the largest information leaks in US history.