A man has been arrested in New South Wales on suspicion of murder and will be extradited to Queensland after human remains were found in a buried fridge at an Ipswich home, police said.

Two fridges were found during Monday's excavation of a Goodna backyard owned by missing 58-year-old man David Thornton, who disappeared more than five weeks ago.

Queensland detectives said the 24-year-old man, who allegedly knew the victim, was arrested in Byron Bay about 11am on Tuesday.

An extradition hearing was expected in the local magistrates court on Wednesday.