Around 40 guests staying at the Newcastle Thistle hotel have been struck down by illness.
The victims, who were all staying at the Thistle hotel, are believed to have contracted the winter vomiting bug.
The 115-room, three-star hotel Thistle hotel, which is opposite Newcastle Central Station, is popular with tourists and business people.
A doctor was called to the hotel on Boxing Day after guests from a coach party reported suffering agonizing stomach pains, diarrhoea and vomiting while staying there over the weekend.
An investigation has been launched by Newcastle City Council. Stephen Savage, head of public health and environmental protection at the council, said: "Although we're awaiting confirmation of our investigation it's likely the infection is viral, otherwise known as the winter vomiting virus. "Most residents have now recovered. Everyone at the Thistle has been extremely co-operative."
A Thistle spokeswoman said: "A doctor was called to the hotel to treat all affected guests and we've assisted environmental health officers with their investigations into the cause of this illness.
"Many of the guests have now recovered and returned home on Wednesday morning," she said.
The winter vomiting bug is caused by a virus that spreads in crowded areas.
by Nigel Green