A major search was under way today for a Sussex man who disappeared during a stag night trip to Belgium.

Best man Ian Gilbert, 25, an advertising rep from Crowborough, helped organise the night out in Ostend for groom Mark Rosier and 25 friends.

But today Mr Gilbert's wife of one year, Charlotte, was distraught amid fears he could have fallen into the sea while walking back to the hotel in the early hours of Saturday morning.

Sussex Police were liaising with Belgian detectives in a bid to trace Mr Gilbert, known as Golly, who has two step-children with his 34-year-old wife.

Close family friend Paul Gray, from Crowborough, who returned yesterday from the stag night, said on behalf of Mr Gilbert's family: "We are all very concerned about Golly's disappearance.

"It is very unlike him to go off without letting anyone know where he is."

Two members of the stag party, all of whom are members of Crowborough Rugby Club, have stayed behind in Ostend to help police search for Mr Gilbert.

The pair, one of whom is a police officer, have distributed dozens of posters carrying Mr Gilbert's photograph.

Mr Gilbert's friends back home have put together a £5,000 reward for information.

The group visited several bars in the town on Friday night to celebrate 27-year-old Mr Rosier's wedding in two weeks' time.

In the early hours of Saturday, all but two of the group made their way back to their hotel. According to his friends, Mr Gilbert was among the party who set off for the hotel.

But, without anyone noticing, Mr Gilbert mysteriously disappeared during the walk which took in the seafront.

Mr Gilbert was first noticed missing later on Saturday morning.

Mr Gray said: "We have been searching along with police in Belgium. We have visited all the local hospitals and we have retraced out steps from the walk that night, but so far we have found nothing.

"As far as we know Golly has not used any of his bank cards. We are all so worried."

Sussex Police say as yet there is no evidence that Mr Gilbert's disappearance is suspicious.

A spokesman said: "The Belgian police are taking the search very seriously indeed. They are actively pursuing inquiries."

Mr Gilbert has blond hair and blue eyes and was wearing blue jeans and a blue shirt when he went missing.

His wife was too upset to comment.