Swedish prosecutors will drop their investigation into sexual assault allegations against Julian Assange on Thursday because of the statutes of limitation.
The Wikileaks founder still faces the more serious allegation of rape.
But prosecutors have run out of time to investigate Mr Assange for sexual assault because they have not succeeded in questioning him.
He denies all allegations and has said they are part of a smear campaign.
The Australian journalist and activist sought asylum in the Ecuadorian embassy in London in 2012 to avoid extradition to Sweden.
Under Swedish law, charges cannot be laid without interviewing the suspect.
Prosecutors had until 13 August to question Mr Assange about one accusation of sexual molestation and one of unlawful coercion, while the time limit on a further allegation of sexual molestation runs out on 18 August.
The more serious allegation of rape is not due to expire until 2020.
An official announcement from the prosecutor's office is expected on Thursday night, New Zealand time.
Mr Assange has always denied all the accusations and said he fled into the Ecuadorian embassy because he feared being extradited from Sweden to the US and put on trial for releasing secret American documents.
He has said in the past that he will not leave the embassy, even if the accusations of sex crimes are dropped.
The woman who accused Mr Assange of sexual molestation and unlawful coercion - who is identified in legal papers only as AA - is said to be relieved that the case is now behind her.
"She had wanted him to stand before the court and answer the accusations but it's five years ago and she's not interested in going to court now," her lawyer, Claes Borgstrom, told the BBC.
"She wants to put it all behind her. It's been a difficult time for her and she's now trying to forget about it and move on with her life."
Swedish prosecutors had initially insisted that Mr Assange be questioned in Sweden, but earlier this year - under pressure to advance the investigation - she agreed that he could be interviewed in London.
But the Swedish government has been unable to negotiate access with the Ecuadorian authorities, with both sides blaming the other for the impasse.
'Difficult and costly'
Lawyers for Mr Assange said the allegations of sexual assault should have been dropped long ago.
"Our position is that the investigation should have been shut down earlier because there wasn't enough evidence to keep it going," Thomas Olsson, one of his Swedish lawyers said.
"It's regrettable that it's gone on for this long."
He said he believed Mr Assange could clear his name over the rape allegation.
"We are convinced that as soon as he has the opportunity to give his version of the circumstances, there'll be no need to continue the investigation."
Sweden is expected to continue discussions with Ecuador over the terms under which the prosecutor could question Mr Assange over the remaining accusation.
The UK government has urged Ecuador to co-operate, stressing that the UK has a legal obligation to extradite Mr Assange.
"We are clear that our laws must be followed and Mr Assange should be extradited," a UK Foreign Office spokeswoman said.
"As ever, we look to Ecuador to help bring this difficult, and costly, situation to an end."
The cost of policing the Ecuadorian embassy in Knightsbridge for the past three years now stands at around £12m ($18.8m; €16.8m).