A male model who murdered a man and buried his body in an olive grove has apologised in court to his victim's family.

Steven Zenuni, 21, pleaded week pleaded guilty to murdering Edward Camilleri, 50.

Mr Caimilleri's body was found buried behind a house in Two Wells north of Adelaide in August 2011 several months after he went missing.

After hearing victim impact statements from Mr Camilleri's parents and two sisters, Zenuni composed himself and apologised directly to them.

He said Mr Camilleri did not deserve to die and he was ready to accept his fate because he would never forgive himself.

Zenuni's lawyer asked the Supreme Court to fix a non-parole period shorter than the mandatory 20-year minimum because of his client's youth, remorse, cooperation with the prosecution and his guilty plea.

He will be sentenced later.

A second man is due to stand trial for the murder this week.