Palmerston North police are investigating after an empty raft was seen floating downstream in the Manawatu Gorge this morning.

The mainly white raft, complete with oars, was first sighted in the Manawatu River at approximately 2 km south of Gorge Road, about 10.30am.

The Police search and rescue squad were currently retrieving the raft, and a helicopter had made several sweeps of the area trying to locate whoever may have been using the raft, a spokesman said.

Anyone knowing anything about the raft and/or its owner is asked to contact Palmerston North Police immediately on 06 351 3600.