A major search is underway as a German reality TV star and singer, reported missing on a cruise from Europe to Canada, is feared to be lost overboard.

Aida Cruises said there was reason to believe that Daniel Kueblboeck, who first found fame as a contestant on the German version of Pop Idol in 2003, jumped into the sea on Sunday morning.

“That is our suspicion,” cruise line spokesman Hansjoerg Kunze said.

The 33-year-old, who failed in his bid to be chosen as Germany’s entry in the 2014 Eurovision Song Contest, was travelling as one of about 2200 passengers aboard the AIDAluna on their way to Newfoundland from the German port city of Hamburg.

The German newspaper Bild, reported that a witness saw someone jump from the fifth deck of the ship.

Mr Kueblboeck found fame on a reality TV competition. Photo: Getty

The incident occurred about 100 nautical miles (about 185 kilometres) north of the city of St John’s on Newfoundland. The water temperature was recorded at about 10.5 degrees Celsius.The AIDAluna  has returned to where the incident is thought to have occurred to help with what Mr Kunze described as “an intensive search”.

The Canadian coastguard confirmed on Monday morning that it was using a surveillance plane and helicopter to search the cold Labrador Sea. Two other cruise ships also helped with the search.

Mr Kueblboeck’s management company could not be reached for comment.

Mr Kueblboeck, born in Bavarian Hutthurm, made his last big television appearance in the eighth season of the show Let’s Dance in 2015 and was studying to be an actor at the European Theatre Institute Berlin.

British woman Kay Longstaff last month survived 10 hours adrift  in dark open waters after falling from a cruise ship in the Adriatic Sea.

Ms Longstaff, 46, was rescued after spending a terrifying night in waters about 95 kilometres off the coast of Croatia.

A Croatian rescue ship found her swimming not far from where she was believed to have fallen.

If you or anyone you know needs help, please contact Lifeline on 13 11 14 or beyondblue on 1300 224 636.

-with agencies