The Centre for Health Protection is probing a suspected food-poisoning case that made six men and six women ill during their travel to Thailand from December 15 to 19.
The group, aged 15 to 61, suffered diarrhoea, stomach pains and nausea.
Five sought treatment from doctors and no one was admitted to hospital.
Initial investigations suggest bacteria is the likely cause of the outbreak. Click here to see tips to guard against food poisoning.
