Only three Australian news brands - two of them national broadcasters - rated positive scores in Roy Morgan's Media Net Trust survey.

The survey conducted in May, showed the ABC and SBS as Australia's two most trusted media brands, with Fairfax Media in third as the only other media brand with a positive NTS.

Newspapers as a whole scored a category NTS of minus 13 per cent, ahead of social media (minus 42 per cent) and television (minus 16 per cent). More trusted than newspapers are the internet (minus seven per cent), magazines (minus four per cent) and radio (minus two per cent).

The survey indicates that Facebook - and social media generally - is deeply distrusted in Australia. Half of all Australians (47 per cent) distrust social media, compared to only nine per cent who distrust the ABC.

Roy Morgan chief executive Michele Levine says that while trust is now firmly on corporate Australia's agenda, "distrust is the critical measure everyone's ignoring".

"Distrust is where our deepest fears, pain, and betrayal surface - the shock of discovering we were foolish to trust too much. And nowhere is that sense of betrayal more profound than in our media brands."

A Net Trust Score or NTS is calculated by subtracting distrust from trust.

Banks score an NTS of minus 18 per cent, compared to the media industry's minus seven per cent, "less toxic than banks, but still in negative territory.

"Australians told us that their trust of the ABC is driven by its lack of bias and impartiality, quality journalism and ethics," says Levine, "while their distrust of Facebook and social media is driven by fake news, manipulated truth, false statistics and fake audience measurement."

The survey indicates that the top-five drivers of distrust in commercial television are false news/fake news, bias, news that is sensationalised/focussed on controversial stories; pushing a commercial or political agenda, and "too much advertising".

In the survey about 4000 Australians were asked which brands they trust and which they distrust. So far four rounds have been conducted - in October 2017, and January, February and April 2018. In May 2018, an additional survey of 1111 Australians asked which media they trust and distrust. Roy Morgan says the survey was unprompted and open ended (quantitative + qualitative) with respondents recruited from the Roy Morgan Single Source database (>600,000)

Respondents were also asked why they trust or distrust nominated media brands.