More than 70 people on a P&O Cruises month-long round-trip voyage from Southampton have come down with a sickness bug.

The outbreak has occurred on the 1,959-passenger Arcadia during its current sailing from the UK to the US and Canada.

Some 65 passengers and 10 crew members have reported symptoms of a gastrointestinal illness including vomiting and diarrhoea, according to the US health agency, the Centers for Disease Control and Prevention (CDC).

It said the cause was unknown.

A P&O Cruises spokesperson said: “Upon embarkation all guests were provided with an advisory notice with precautionary health measures for on board and on shore, as is standard procedure across our fleet. (Following reports of guests with gastrointestinal symptoms,) P&O Cruises swiftly implemented approved, proven and enhanced sanitisation protocols to uphold the wellbeing of everyone onboard.”

It is understood CDC officials boarded the ship while it was docked in New York from 18 to 20 September but no sick passengers disembarked and the cruise was not delayed.

Arcadia, which left Southampton on 3 September, is currently sailing from Portland to Saint John in Canada. It is due to arrive back in Southampton on 3 October.