Clifford Olson, then 41, leaves provincial court in Chilliwack, B.C., on Aug. 8, 1981. (Canadian Press)

Serial killer Clifford Olson's threat to fight to keep his old age pension is "deeply insulting to his victims and their families," says Canada's human resources minister.

Olson, one of Canada's most notorious serial killers, is threatening to take the federal government to court over its plan to end pension payments to federal inmates like himself.

In a written statement sent to CBC News Friday, Human Resources Minister Diane Finley said: "Canadians are outraged that prisoners like child-killer Clifford Olson are receiving taxpayer-funded benefits.

"Prisoners already have their basic needs met in prison by taxpayers," she said.

"We will not forget the crimes committed by Clifford Olson and his desire to maintain his taxpayer-funded entitlements is deeply insulting to his victims and their families. This bill is the fair and right thing to do."

Last month, the government announced a bill that would end pension payments to some federal prisoners.

The move came after it was revealed that Olson was eligible to collect $1,100 a month in seniors benefits and income supplements.

The new bill would deprive about 400 federal prisoners of about $2 million a year in benefits if it becomes law.

Olson has spent the last 28 years in prison for killing at least 11 boys and girls in British Columbia.

He has sent a three-paragraph letter to Ottawa saying he looks forward to a court case if his old age pension is taken away.

His retirement benefit money has been put in trust. He was also paid $100,000 by the RCMP to lead them to the bodies of his victims. That money was put in trust for his estranged wife and son.

With files from The Canadian Press