Hospitals serving Camden have been forced to write off �2.45million in unpaid bills for treatment of foreign patients in the last four years.

The sum was incurred treating foreign visitors to the UK who are not eligible for free NHS healthcare but have used hospitals for treatment and then not paid.

The three hospitals serving Camden – the Royal Free Hospital in Hampstead, the Whittington Hospital in Highgate, and University College London Hospital (UCLH) in Euston – have provided figures for unpaid foreign debts over the last four years.

The Royal Free was the worst affected writing-off �1.78million in overseas debt over the period.

But the annual level of foreign debt has fallen significantly from �654,000 in 2009-2010, to �457,000 in 2010-2011 and �354,000 in the last financial year.

A Royal Free spokeswoman said: “Our overseas patient written-off debt has decreased over the last three years, which we believe is due to improvements in our processes.

“Wherever possible we seek to recover payment for the cost of treatment either before or during a patient’s period of care at the hospital.

“If this is not possible for any reason we work closely with our credit control team and in some cases the UK Border Agency to follow up with individuals or family members to attempt to secure payment.”

The overseas debt written-off by the Royal Free this year represents just 0.07 per cent of its �486million total income.

But it is still much higher than at UCLH, which wrote-off �443,397 in the three years to 2011 and is yet to release its figures for the last financial year.

The senior member of finance at the Royal Free attributed the hospital’s higher figure to a large Accident & Emergency (A&E) department and the specialist services it offers, such as haemophilia and liver services.

A UCLH spokesman highlighted the difficulty securing overseas payments and said: “We have an overseas visitors team to identify overseas patients and then raise invoices.

“If these are not paid, we have limited powers to force payment. These debts are often uneconomic or impossible to collect once patients return home overseas.”

The Whittington Hospital had the lowest amount of unpaid foreign debt, writing off �227,578 over the last four years.

Health Minister Simon Burns said: “There are comprehensive rules and procedures to charge visitors for hospital treatment but we know that the system needs to be improved.

“That is why we are currently reviewing those arrangements to prevent inappropriate free access to the NHS and provide a fairer more balanced system.

“Hospitals have a legal duty to recover any charges made to overseas patients.

“The government has also recently amended the immigration rules so that anyone with an unpaid debt to the NHS of �1,000 or more can be refused a new visa.

“The NHS has a duty to anyone whose life or long-term health is at immediate risk, but it is not there to serve the health needs of the globe.”