"Assange was always willing to answer any questions from the Swedish authorities and repeatedly offered to do so over six years… This investigation has been dropped before and its reopening will give Julian a chance to clear his name", Hrafnsson said in a statement posted by WikiLeaks on Twitter.
Earlier in the day, Swedish prosecution announced the reopening of the investigation, just over a month after Assange was stripped of his political asylum by Ecuador and arrested at the Ecuadorian embassy in London.
Sweden is reportedly hoping to have some "indication" from the United Kingdom on Assange's extradition in the summer.
Rape allegations, after Assange's visit to Sweden in 2010, were the main reason for him to seek asylum in London's Ecuadorian embassy back in 2012 when a warrant was issued for his arrest.
On 1 May, a court in London sentenced Assange to 50 weeks in prison for breaching bail by seeking refuge in the Ecuadorian Embassy. The UK police detained him in the embassy in April after the Ecuadorian government withdrew asylum.
The United States is seeking Assange's extradition on charges of conspiracy to commit computer intrusion. However, WikiLeaks said in April the United States might be building an espionage case against Assange. This charge carries death penalty as a maximum potential sentence.