Another two arrests have been made by police investigating the alleged murder of Adelaide man Geoffrey McLean, whose torso was found in a wheelie bin in October.

The 51-year-old man and 50-year-old woman are both from the northern suburbs and are being questioned by detectives.

SA Police said it expected to charge the pair later this evening with assisting an offender following Mr McLean's alleged murder.

Major crime detectives and forensic police are currently searching a Brahma Lodge home.

The man and woman will appear in the Adelaide Magistrates Court on Tuesday, police said.

There have now been four arrests in relation to the alleged murder of 55-year-old Mr McLean, who was last seen alive in August, two months before his torso was discovered by a gardener on Cheviot Road in Salisbury South.

A 49-year-old Andrews Farm woman charged with murder earlier this month was allegedly known to the victim.

Her 51-year-old co-accused faced the Adelaide Magistrates Court earlier this month, also charged with murder.

He was additionally charged with several other serious offences, including attempted murder, aggravated assault and serious criminal trespass, relating to a series of attacks on Mr McLean in April and May last year.

Police have urged anyone with information regarding the attacks, the murder, or the aftermath to contact Crime Stoppers.