Australia's broadcast media watchdog has dismissed complains that an ABC Four Corners report about WikiLeaks publisher Julian Assange was inaccurate and biased.

A lengthy investigation by the Australian Communications and Media Authority has found that the Four Corners program Sex, Lies, and Julian Assange, broadcast in July 2012, did not breach the ABC's Code of Practice.

The ABC report by veteran investigative journalist Andrew Fowler examined allegations of sexual assault and rape made by two Swedish women against Mr Assange in August 2010 and subsequent criminal investigations and extradition proceedings by Swedish prosecutors.

The program also discussed the possibility that Mr Assange could be extradited to the US to face charges related to the leaking of thousands of classified US diplomatic and military documents by US Army private Chelsea Manning, formerly known as Bradley Manning.

Two complainants asserted that Four Corners presented inaccurate information, omitted relevant information and was biased in favour of Mr Assange.

One of the complainants claimed that the entire report was “skewed very heavily towards presenting only Julian Assange's perspective while ignoring the legitimacy of the Swedish case or the perspective of the two Swedish women who made the allegations.”

The ABC submitted that the program included “a broad range of principal relevant perspectives, none of which were unduly favoured over any other. It is important to understand that impartiality does not require that every perspective requires equal time, nor that every facet of every argument is presented.” After a 17-month investigation, the ACMA concluded that Four Corners presented factual material and opinions accurately.

ACMA observed that the ABC was “entitled to present and explore Mr Assange's perspective, as long as the material has been presented accurately, doesn't convey a prejudgment and does not unduly favour one perspective over another.”

The ACMA noted that the two Swedish women were invited to be interviewed for the program but declined, but that their perspectives were presented by their lawyer and by interviews with the Swedish prosecutor's office. The program also included footage of the former US ambassador to Australia, Jeffrey Bleich, saying Mr Assange's circumstances were “not something that the US cares about, it's not interested in it, it hasn't been involved in it.”

ACMA observed that Mr Fowler maintained “a relatively neutral tone” throughout the report and did not use “sustained emotive or colourful language.”

“The segment made it very clear that there were opposing views … impartiality does not require that every perspective receives equal time, nor that every facet of every argument is presented.”

Mr Fowler told Fairfax Media that it was “pleasing that a painstaking investigation has completely vindicated Four Corners, finding that we were accurate and impartial.”

Mr Assange has resided at Ecuador's London embassy since June 2012 and has been granted political asylum by Ecuador on the grounds that he is at risk of extradition to the US to face conspiracy or other charges.

British police are on guard outside the embassy 24 hours a day, waiting to arrest the WikiLeaks publisher so he can be extradited to face questioning in Sweden about the sexual assault allegations. Mr Assange's lawyers have advised that his extradition to Sweden could facilitate his extradition to the US.

The US government began a criminal investigation focused on WikiLeaks and Mr Assange in 2010. Mr Assange was identified by US prosecutors during Private Manning's court martial last year as an alleged co-conspirator, guiding and directing the soldier's disclosure of classified information. As recently as last August, the US Justice Department confirmed that its investigation of WikiLeaks was active and ongoing.