Rare intervention in Snowtown accomplice’s case before he is released

A man who helped cover up Australia's worst serial killings is due to be released from prison within a matter of months.

When Mark Ray Haydon has served his time for his role in the Snowtown murders he may not be subject to surveillance, given he will have completed his full sentence.

As a result, the South Australian government is intervening with a rare application to the Supreme Court in a bid to keep watch over the 65-year-old once he is freed.

"I can announce today that the attorney-general has issued instructions to the Crown to pursue an extended supervision order against Haydon," Premier Peter Malinauskas said.

"It is the government's position that Mr Haydon falls within the definition of a high risk offender. That is he assisted after the fact in a very serious, violent set of crimes," Attorney-General Kyam Maher added.

If the government's application to the court is granted, it will mean when Haydon is released he will still be monitored and bound by strict controls.

These can include electronic monitoring and curfews.

"Our job as a government is to do everything we can to keep the community safe," Malinauskas said.

In a separate decision, the Parole Board is due to meet tomorrow to decide whether Haydon should be granted early release.

If granted, this will be another move aimed at monitoring Haydon, rather than releasing him into the community without any surveillance.

That decision is expected in the coming days.

The Snowtown murders are Australia's worst serial killings, and Haydon was one of four people arrested in 1999 when the bodies of some of the 11 victims were found in barrels, in a disused bank vault, in the state's mid-north.

Those barrels had also for a time been stored at Haydon's northern Adelaide home, and among the victims was his own wife.

Haydon was jailed for at least 18 years for assisting John Bunting and Robert Wagner in seven of the 11 killings.