A search was under way today for a 25-year-old Sussex man who disappeared during a stag night trip to Belgium.

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

Mr Gilbert disappeared during the walk back to their hotel in the early hours of Saturday.

Friends and family fear he may have fallen into the sea.

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

Close family friend Paul Gray, of Park Lane, Crowborough, who returned from the stag night on Sunday, 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.

"His wife, who he only married a year ago, is distraught. We are all devastated. He is a real family man. He and Charlotte are so happy together.

"We are doing everything we can to aid the search for Golly. We are all very distressed, as you can imagine. It's a very difficult time for everyone."

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

The pair, one of whom is a police officer, have distributed dozens of posters showing his 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 them 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, he mysteriously disappeared during the walk which took in the seafront.

Now there are fears he may have slipped into the sea undetected.

Mr Gilbert was first noticed missing on Saturday morning.

Mr Gray said: "We have been searching along with police in Belgium.

"We have visited all the local hospitals and have retraced our 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.

"Our priority now is to find out what has happened. Golly is a lovely bloke which is why we are trying so hard to find him."

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.

"Mr Gilbert was with a group of friends when he went missing. His friends saw him in a bar but have not seen him again.

"We are liaising with Belgian police and so is the National Missing Persons Register."

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