An elderly British tourist has died at a hotel on Italy's Lake Garda where dozens more visitors were taken sick with suspected food poisoning, officials said on Wednesday.

About 40 people fell ill at the weekend at a hotel in the town of Gardone Riviera, in northern Italy, with symptoms including fever, vomiting and diarrhoea, and 27 of them were taken to hospitals in the area.

Health officials said the preliminary diagnosis was food poisoning caused by salmonella, a bacteria that can be transmitted by infected or badly prepared food, but that could not be confirmed until more tests were carried out.

The victims included a 71-year-old man who died on arrival at a hospital in the town of Gavardo, and 17 British holidaymakers who were in hospital recovering.

Britain's deputy consul in Milan, Stephen Anderson, said the cause of the man's death could only be determined by a post mortem.

"He was staying at the same hotel," he told Reuters.

The tourists were taken ill at the four-star Grand Hotel Gardone Riviera in the northern region of Lombardy. Garda is the largest lake in Italy and a major tourist destination, with many exclusive hotels and villas along its shore.

Hotel manager Franco Mizzarro said tests had not yet shown "what caused the illness the people have". Tourists were still using the hotel pool and walking along the shores of the lake.

"The hotel is operating normally, we served meals using a catering service," Mizzarro told Reuters Television.