Police are responding to an “incident” on board an oil tanker off the Isle of Wight amid reports of an attempted hijacking.
A Coastguard helicopter was spotted circling the vessel on Sunday afternoon and an exclusion zone has been set up in the area south of Sandown.
The ship is a crude oil tanker named the Nave Andromeda, according to the Isle of Wight Radio.
The Liberian registered oil tanker is said to have given out a mayday call at 9am.
It is understood that the 228-metre tanker had been expected to dock in Southampton at 10.30am on Sunday.
A Hampshire police spokesman said: “We are aware and dealing with an ongoing incident on board a vessel which is situated south of the Isle of Wight.
“We will provide you with further updates when we are in a position to do so.”
A HM Coastguard spokesperson told the Isle of Wight Radio: “We are currently assisting Hampshire Constabulary with an incident on board a vessel situated off the Isle of Wight.
“The search and rescue helicopters from Lee on Solent and Lydd are in attendance.”
A spokeswoman for Associated British Ports (ABP), which runs Southampton port, said they had not had any contact with the vessel and they had no further comment.