Searches for Michael Dixon are being conducted in Costa Rica
The parents of a British man who went missing during a trip to Costa Rica have appealed for help in tracing him.
Michael Dixon, 33, checked into the Villas Macondo hotel in Tamarindo, Guanacaste, on 18 October.
The last confirmed sighting of him was in the afternoon of the same day when staff saw him leave the hotel.
His mother, Lynn, told a news conference in London: "We are very close to our son... and we are desperate to find him."
Mrs Dixon, who lives in France with Michael's father, Hubert, said the past weeks had been a "nightmare".
She said: "So far, the air, sea and land searches have not turned up any evidence about what has happened and we continue to wonder how he could have simply disappeared without explanation."
She described her son as caring and considerate, with a great sense of humour.
The press conference heard that when the Leeds University graduate went missing it was at the height of the rainy season and there was no lifeguard on duty at the popular surfing beach.
Hubert Dixon said: "You never think that something like this could happen to you and suddenly you're faced with the fact that your son is gone and you might never see him again.
"The thing is that there's no explanation. If there was some reason, perhaps we could accept it a bit easier."
The Costa Rican ambassador to the UK, Pilar Saborio, told the news conference that police investigating Mr Dixon's disappearance had so far found no evidence of foul play.
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The ambassador told Mr Dixon's parents she understood their anguish and frustration.
She said: "We would like to reassure you, though, that we, the authorities in Costa Rica, are doing everything in our power to search for Michael and to get to the truth of the matter."
Mr Dixon, who was born in Salford but grew up in France, was reported missing to local police by hotel staff on 21 October.
When police searched his room they found it undisturbed, with his phone, glasses and wallet still there.
The Brussels-based journalist edits a magazine for the pulp and paper industry.
His family became concerned when he failed to return to work on 26 October.
Relatives then flew out to Costa Rica and have carried out searches involving the Red Cross and local volunteers.
A team of sniffer dogs from the US has now arrived at the resort to assist with the search.
The news conference was organised by Missing Abroad, a scheme run by the Lucie Blackman Trust. The trust was set up by Tim Blackman after his daughter was killed while working in Tokyo in 2001.