The most senior police officer in the East Riding has vowed to never give up the search for Russell Bohling.

Chief Superintendent Paul Davison admits the force is baffled by the 18-year-old's disappearance, but insists he owes it to the family to keep looking.

His comments come after the coastguard revealed Russell's body may never be found if he ended up in the sea.

The Bishop Burton student's car was found at Bempton Cliffs on March 2, with a day's parking paid up but Russell was nowhere to be seen.

Two months on and there is little evidence to shed light on his whereabouts.

Chief Supt Davison said: "We will never abandon this case.

"No effort will be spared and everything that can be done will be done to find Russell.

"We have nothing to suggest he's alive but we also have no body.

"We will put resources into any line of inquiry but there may come a time when we will just have to wait for new evidence to come in before we can act."

Maritime and Coastguard Agency spokesman Mark Clark explained that finding Russell, if he did end up in the sea, could be an impossible task.

He said: "A body entering a strong water column at Bempton may end up trapped in rocks or will sink to the bottom.

"The body may rise for a few hours but after that, it will sink forever.

"The body won't move very much and would likely remain close to where he went in.

"But the body may never be found."

Chief Supt Davison has brought in outside help to ensure every avenue is explored.

He was due to meet a detective from another police force yesterday evening to discuss the way forward.

A representative from The National Policing Improvement Agency (NPIA), a police-owned body which supports police forces to improve the way they work, is also being brought in.

Chief Supt Davison said: "What we do next will depend on this external review.

"We could look at either scaling it down or stepping up the investigation.

"But it is unlikely we would scale down at this stage.

"Once the review is complete, we will sit down and look at what our plan is for the future."

As well as the cliffs, much of the initial search centred around the mysterious underground network known locally as 'Bempton Tunnels'.

The subterranean structure is actually an abandoned RAF base built during the Second World War.

The tunnels are particularly important as Russell, from West Ella, downloaded information about them on his computer just days before he went missing.

The entrance to the base is on privately owned land, fenced off from the public.

The base is considered dangerous and contains asbestos.

A spokeswoman for Humberside Police revealed extensive searches have continued since Russell's disappearance, including the disused RAF base.

She said: "The searches have not stopped since the initial reports of Russell's disappearance.

"We have searched all the derelict RAF buildings and have brought in specialist Fire Service teams during the asbestos searches.

"The base has been searched thoroughly.

"Other searches have included the parameter of Bempton, the cliff tops and cliff base.

"We have involved the mountain section, dog section, air support, the marine section and the lifeboat.

"We have left no stone unturned."

Meanwhile, Bishop Burton College has responded to criticism made by the family during a press conference on Tuesday over their lack of contact to express sympathy.

A spokeswoman for the college said: "This must be a terrible time for the family and the students and staff of the college are united in the hope that Russell is found safe and well."