KILLERS, paedophiles, robbers and a man who raped his daughter and fathered her four children, were receiving the Disability Support Pension when they committed their crimes.

Court and tribunal judgments show the criminals were claiming the pension for reasons including alcoholism, smoking, learning difficulties, bad backs and depression, even though some were later employed in prison jobs.

The Victorian father who subjected his daughter to hundreds of rapes received the DSP from 1996 for "smoking and alcoholism".

The man in his late sixties, who left his job because of "problems with alcohol", was on the DSP when three of the children were born over a four-year period starting in the late 1990s.

In another case a middle-aged Victorian man who befriended a 15-year-old teenage girl online and then took her from her NSW home and sexually abused her for weeks, was claiming the pension because of "learning difficulties".

Murderer James Martin Mulhall, 59, who strangled and smothered his partner Joy Rowley in October, 2011, was first put on the dole because painting became "too physically demanding" - and moved to the DSP in 2008.

Wayne Joseph John Castle who pleaded guilty last December to the manslaughter of freelance journalist Jennifer Maree Smith during a robbery in Newtown in Sydney's inner west in January 1998, began receiving the DSP following his offence. He was hit by a car in 2008 leaving him "sufficiently impaired to prevent him working".

A father who forced his own son to have sexual intercourse with his mother, began receiving the DSP after he first suffered a back injury while working for the Victorian government and a subsequent milk bar business failed. A judge last September described the man's crimes as "depraved".

More than 824,000 Australians receive DSP payments of up to $733 a fortnight at an expected cost of almost $15 billion to the budget this financial year, with reforms started in 2010 resulting in just 7826 people coming off the DSP.

Community Services Minister Jenny Macklin has introduced tighter impairment tables for new applicants, who have to prove they can't work and who are subject to scrutiny by a new Health Professional Advice Unity in Centrelink.

The criminals were legally entitled to receive the DSP and Ms Macklin's spokeswoman said existing recipients could be subject to review and payments were also stopped for recipients who were jailed.

"Our DSP reforms have improved the quality of assessments and provide better support," she said.