Holiday revellers who fall ill and visit doctors and clinics in other countries are often subjected to unnecessary treatments resulting in huge bills, according to travel insurance company Gouda. The problem is particularly bad for those who get sick while travelling in Turkey, Egypt and Greece.

"We’ve seen a number of examples where patients were nearly held hostage and had their passports taken from them until the hospital received a guarantee of payment," Gouda spokesperson Karin Tranberg told DR News.

Tranberg cited the example of a Danish man hospitalised for stomach problems while in Greece. The treatment should have cost only a couple of hundred euros, but after the man was forced to undergo a battery of unnecessary tests he was handed a bill of 15,000 kroner. He was only released from the hospital after he signed a guarantee that he would personally pay whatever portion of the bill that his insurance did not cover.

"Travellers should call their insurance company immediately in case of an emergency so they do not receive unnecessary over-treatment,” said Tranberg.

Tranberg said that Gouda averages about 1,000 calls per week from Danish travellers who fall ill while on holiday. Most are suffering from stomach problems.