Hospitals are owed hundreds of thousands of pounds in unpaid fees for treatment carried out on overseas patients.

Department of Health guidance says hospitals should identify and charge so-called health tourists from abroad.

However Sussex hospitals have outstanding bills totalling more than half a million pounds for treatment over the past five years.

The NHS had a duty to provide treatment for patients with urgent problems coming into A&E although it can charge for subsequent care.

Efforts are made to trace the patient and claim back money owed but once every avenue has been exhausted, organisations have no other choice than to write the debt off.

This has an impact on trusts which are struggling to keep their already tight finances under control.

Brighton and Sussex University Hospitals NHS Trust, which runs hospitals in Brighton and Haywards Heath, has the highest outstanding amount - £492,887 owed by 132 people.

This includes a bill of £82,639 for neurological, intensive care and rehabilitation treatment. The trust has written off £217,255 since 2010, which can be done if the criteria meets Department of Health guidance.

This could be if a patient has subsequently died and recovery from their estate is impossible or if their financial circumstances mean it would not be cost effective to pursue it.

For example this might be a failed asylum seeker or someone genuinely without access to any funds or other resources to pay their debt.

A spokesperson for Brighton and Sussex University Hospitals said: “The trust follows the Department of Health’s regulations to identify and charge overseas patients for the hospital treatment they receive.

“We have processes in place to charge patients who are not entitled to free care.

“There are occasions where this is difficult or not possible and, in common with all hospitals, we report these cases to the Department of Health.”

Western Sussex Hospitals NHS Trust is owed more than £60,700, including £4,267 for a patient whose heart had stopped.

East Sussex Healthcare NHS Trust, which runs hospitals in Eastbourne and St Leonards, is owed £50,279, including £10,200 for an operation.

NHS Services for overseas patients

Some NHS services are free to everyone regardless of the status of the patient.

Accident and emergency services, whether provided at a hospital accident and emergency department, a minor injuries unit, a walk-in centre, or elsewhere, up until the point an overseas visitor is accepted as an inpatient or given an outpatient appointment.

Family planning services, which means services that supply contraceptive products and devices to prevent establishment of pregnancy.

Certain diseases where treatment is necessary to protect the wider public health, such as measles, mumps, malaria and Legionnaires Disease.

Treatment for all sexually transmitted diseases, including HIV treatment.

NHS bodies must also ensure that treatment which is immediately necessary is provided to any patient, even if they have not paid in advance.

Failure to provide immediately necessary treatment may be unlawful under the Human Rights Act.