Swedish prosecutors have dropped a rape investigation against WikiLeaks founder Julian Assange, ending the near decade-long case that had sent the anti-secrecy campaigner into hiding in London's Ecuadorian embassy.

The Swedish Prosecution Authority said the corroborating evidence had weakened considerably "due to the long period of time that has elapsed since the events in question".

The investigation was first opened after the alleged incident in August 2010 but closed in 2017, before being reopened earlier this year when Assange was arrested after being dragged out of the Ecuadorian embassy in London.