Tauranga Police are investigating sexual assault allegations made against a crew member of a cruise ship.

The Millennium liner docked at the Port of Tauranga yesterday morning after sailing from Fiji.

Police are investigating an alleged sexual assault aboard The Millennium. Photo: Supplied.

Detective Sergeant Pete Blackwell says a woman in her late 40s, early 50s, is accusing one of the crew members of indecently assaulting her while the liner was in Fiji waters.

"We had a team of invesigators on the ship yesterday looking into the allegations."

Pete says the woman alerted the ship's captain who then informed Tauranga Police are soon as they docked at the port.

"We have to have a result into the investigation in the next few days."

The Millennium was due to leave port and head to Auckland yeserday, but was delayed due to the investigation.