SA government wants child porn MP's salary back

South Australian Premier Jay Weatherill will try and claw back disgraced upper house MP Bernard Finnigan's salary after he was found guilty of accessing child pornography.

"It's impossible not to draw the conclusion that those resources have been applied to his defence," Mr Weatherill told FiveAA radio on Thursday.

"... that will be something which just doesn't sit well with the public."

Mr Weatherill said he was determined to recover four years worth of Finnigan's salary, understood to be up to $700,000.

"I wouldn't want to hold out false hope but I think we're duty bound to explore all these things," he said.

Mr Weatherill has also said that if Finnigan refuses to resign, the government will seek to expel him when parliament sits next week.