Julian Assange says reports of Ecuador planning to smuggle him out of its London embassy and of alleged clashes with staff at the diplomatic mission are a "false attack" on him.

In apparent leaks of official Ecuadorian documents, it's reported that officials concocted elaborate escape plans for the WikiLeaks founder to get him out of the UK.

They included disguising him in fancy dress to smuggle him out of the embassy where he's been holed up since 2012 to avoid extradition to Sweden to face rape and sexual assault claims.

Another plan, reported by BuzzFeed News, was to smuggle Assange out in a diplomatic bag.

Further plans to evade police surrounding the embassy involved him becoming lost in the crowds at the nearby Harrods department store or making a dash across rooftops to a helipad.

As well as the escape plots, the documents detail alleged clashes between Assange and embassy security staff and concerns raised about his mental health.

In September 2012 it's alleged a guard found him in an off-limits secure control room in the embassy, leading to a scuffle and the toppling of a computer screen.

The report also notes instances of Assange shouting and talking incoherently at night, attributed to the stress of his situation, and refers to "a need to control access to alcohol".

Assange responded to the media reports in a brief one-line statement on Wednesday, saying: "Yet another predictably false attack in the media during the run-up to the launch next week of our new book on the US-UK relationship The WikiLeaks Files."

Swedish authorities began talks with Ecuadorian officials in Stockholm this week on setting up legal guidelines so Swedish prosecutors could interview Assange at the embassy.

He has been granted asylum by Ecuador and is fearful of being extradited to the US to face espionage charges over damaging WikiLeaks releases of security information.