Government has launched an investigation into the outbreak of illness on the cruise ship Horizon .

The health department's probe comes as it emerged contaminated food was probably to blame.

Investigations also revealed about 220 of the 1,600 passengers on the ship reported symptoms of Salmonella poisoning -- more than three times as many as originally thought.

Several of the 700 crew members also reported symptoms, which included diarrhoea, stomach cramps and fevers.

Nine people needed hospital treatment in Bermuda, although none were detained, and others were cared for by the ship's doctor.

The extent of the illness came to light following inquiries by the United States Centers for Disease Control and Prevention.

"All I can say is that we are looking into the matter,'' Government Chief Medical Officer Dr. John Cann told The Royal Gazette last night.

The president of Meyer Agencies, the ship's agents, said he would be receiving a full report today.

"At present I only know that some people got stomach upsets,'' said the Wor.

Henry Hayward.

Yesterday, the Horizon arrived in Bermuda after it had been given the all-clear by the CDC.

Some passengers voiced their outrage over the second recent health alert involving the ship.

One woman even threatened to launch legal action, claiming her holiday had been ruined.

The CDC said a preliminary investigation found that contaminated food aboard the ship was the probable cause of the sickness.

It was last Tuesday -- one day after Horizon arrived in Bermuda -- that the outbreak started.

The ship docked in New York on Saturday and the CDC carried out an inspection.

According to the New York Times , the CDC found no problems with food storage or preparation.

But a preliminary investigation found that contaminated food aboard the ship was the probable cause of the sickness.

The paper quoted Mr. Al Wallack, senior vice president for passenger services at Celebrity Cruises, which owns the Horizon, as saying all suspect food was dumped on Saturday before the ship departed.

Last summer, 17 confirmed and 34 suspected cases of Legionnaires' Disease were diagnosed in passengers on the Horizon.

One person who had been on the ship died from the disease.