Police began a search for Edward Gillespie on Sunday night. He was last seen in the early hours of Saturday at the Roydon Marina Hotel, Roydon Mill.
When he failed to return to his home in Rosslyn Crescent, Luton, worried relatives reported him missing.
Mr Gillespie’s car was found at the hotel and a police marine unit and specialist search teams were called in.
The search is concentrating on the nearby River Stort, the riverbanks, the hotel and grounds.
Chief Insp Nick Lee said: “We are extremely concerned for Mr Gillespie’s welfare.
“He had been attending a company party at the hotel and was due to stay overnight before checking out on Saturday morning.
“His car and belongings are still at the hotel but there is no sign of Mr Gillespie.
“We want to hear from anyone who might have seen him, possibly walking around outside the hotel in the early hours of Saturday.”
Original Source http://www.bbc.co.uk/news/uk-england-essex-20836107