By Steve Cannane
Over four years after he was granted asylum in the Ecuadorian embassy in London, Julian Assange is set to be interviewed over allegations of sexual assault.
Here is all you need to know about the allegations and why it has taken six years for him to be interviewed.
What are the allegations?
The allegations centre on a trip Mr Assange made to Stockholm in August 2010.
Two women, referred to as Miss A and Miss W, claim that in separate instances they had consensual sex with Mr Assange that became non-consensual when he refused to wear a condom.
The WikiLeaks founder denies the allegations and has not been charged.
Three of the allegations relating to Miss A have already expired due to the statue of limitations. The questioning will be based on a rape allegation made by Miss W which does not expire until 2020.
In 2010 Miss A and Miss W got in touch with each other after the alleged sexual assaults took place, compared stories and went to the police. Soon after the Swedish prosecutor issued an arrest warrant for Mr Assange.
He was questioned by police and the arrest warrant was cancelled.
The Director of Public Prosecutions, Marianne Ny, then ordered that the investigation be reopened.
What happened next?
By the time a Swedish court ruled that Mr Assange should be detained for questioning, he had flown back to London (after being granted permission to do so by Swedish authorities).
His legal team insists he then made himself available for interview at either the Swedish embassy or via video link. Sweden issued an international arrest warrant for him.
In December 2010 Mr Assange handed himself in to British police.
He was granted bail at the High Court after a number of high-profile supporters, including journalist Jemima Khan and filmmaker Ken Loach, stumped up cash and guarantees worth 240,000 pounds ($400,662).
In 2011, a British court ruled that Mr Assange should be extradited to Sweden. His lawyers fought the decision fearing he would end up being extradited to the US from Sweden to face some form of espionage charge relating to the top-secret information he had published via WikiLeaks.
Papers released during legal proceedings in 2014 showed that the US Department of Justice and the FBI had WikiLeaks under “a multi-subject investigation”.