An incident onboard an oil tanker off the Isle of Wight has prompted a police response amid reports of an attempted hijacking.

Attention is on the Liberian-registered Nave Andromeda crude oil tanker south of Sandown, according to Isle of Wight Radio, where the incident is reported to have taken place.

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 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.

It is understood that the 228-metre tanker had been expected to dock in Southampton at 10.30am on Sunday.

Two coastguard helicopters have been scrambled to the scene and were spotted circling the ship on Sunday afternoon, and an exclusion zone was set up in the area south of Sandown.

A Coastguard spokeswoman said: “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 the Home Office said it is aware of the incident.

A Ministry of Defence spokesman confirmed there was no military involvement in the incident.

Bob Seely, Conservative MP for the Isle of Wight, said the incident would be treated as a “marine counter-terrorism” incident and a meeting of the government Cobra emergency committee would be held to discuss the response.

He said he expected specialist units to be scrambled to handle the situation.

He told Sky News: “Despite being told not to drop anchor, the skipper has dropped anchor and the ship may be now under the control of stowaways on the ship.

“I suspect because of the nature of this it will be treated as marine counter-terrorism and the number of people in the UK who do that are very limited and the relevant units will be looking at options no doubt as to what we could be doing.”

A UK Chamber of Shipping spokesman said: “We are aware of an incident onboard the Nave Andromeda off the Isle of Wight and are in contact with the relevant authorities. We believe it is likely to be related to stowaways onboard but are awaiting more information.”

Mick Cash, general secretary of the maritime union RMT, said: “We urge the UK Government to do all it can to prevent any harm coming to crew or anyone else on the Nave Andromeda.

“This is a troubling incident which must not escalate to further jeopardise crew welfare or maritime safety in what is an extremely busy area for merchant shipping.

“We must call on all parties, including the Greek shipowner to take action to resolve this incident safely and quickly.”