KEY POINTS:
An autopsy is expected to be carried out this morning on a woman's body found partially hidden and decomposing on the side of the road north of Morrinsville.
The body was discovered late on Sunday by a motorcyclist who stopped for a rest at a layby on State Highway 27, near Tahuna.
The body had not been identified last night but police said they were treating the death as suspicious.
The motorcyclist went to investigate after noticing a smell coming from an area off the road. He found the body, which was partially covered by scrub and trees, and called the police.
Institute of Environmental Science and Research staff spent yesterday combing the area for evidence and police cordoned off a nearby river and part of the state highway until the body was removed about 5pm.
Detective Senior Sergeant Chris Page said it appeared the woman died recently but he was unable to give a timeframe.
But the body was affected by a degree of decomposition, indicating the woman had been dead for more than a couple of days.
A resident said he was told the body might have been at the layby for at least two weeks. The area was often used as a stopping place by motorists and also as a dumping ground.
Mr Page said a post-mortem examination would establish how long the woman had been dead and the cause of death. He would not comment on whether the body was clothed.
He said 12 officers were working on the investigation. If the autopsy indicated the woman was murdered, the size of the team would be increased in the next few days.
Police are keen to hear from anyone who has used the layby or noticed people or vehicles there.