Snowtown murders accomplice Mark Haydon will be released from prison, 25 years after the bodies of eight victims were found in acid-filled barrels north of Adelaide.

On Wednesday morning the South Australian parole board granted Haydon’s parole, saying he was well-behaved during his 18-year imprisonment.

Haydon was set to be released in May and SA parole board chair Frances Nelson said he would be released earlier to allow supervision.

“His institutional behaviour has been excellent throughout his incarceration,” she said on Wednesday.

“In our view, the community and he would benefit from a period of supervision on parole prior to (his release).”

He will be placed under electronic monitoring until May.

“Not because we think it’s really necessary from his perspective but it will give some reassurance to the community given the notoriety of his offences and the fact it’s attracted so much coverage,” she said.

New legislation was introduced to SA parliament on Tuesday, designed to widen the definition of a high-risk offender to include those convicted of assisting an offender.

Current laws mean Haydon will not be under supervision when he is officially released in May.

Attorney-General Kyam Maher said the new laws would allow the government to apply for parole conditions as long as the Supreme Court agrees.

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

Bunting was convicted of 11 counts of murder and Wagner 10.

Both are serving life sentences with no chance of parole.

Their murder spree killed eight people whose dismembered bodies were found in acid-filled barrels in the vault of a disused bank in Snowtown, north of Adelaide, in 1999.

– AAP