THE NHS is falling hundreds of millions of pounds short in its ambition to claw back money lost through health tourism, a report has revealed.

Analysis from the National Audit Office (NAO) showed that while hospital trusts in England were getting back more money from foreign visitors who were not entitled to free treatment, the health service was on course to miss its targets.

Estimates suggest that of the £500 million the government aspires to recover annually by 2017-18, only around £295 million is likely to be brought in from charges of £346 million.

This, the report said, is "significantly less" than the NHS is capable of recovering from the cost of treating patients from overseas.

It showed attempts to reclaim costs to the health service have been hindered by the failure to identify and charge foreigners from the European Economic Area (EEA) who receive treatment and "particular challenges" in pursuing patients outside of the continent.

A survey from earlier this year showed 42 per cent of hospital doctors and 55 per cent of hospital nurses did not know some people were chargeable, the report said.

Figures from 2012-2013 suggested £367 million should have been charged to foreign patients for treatment - but only £49 million was asked for.

However, progress is being made as the amount collected has risen from £73 million in 2012-13 to £289 million in 2015-16.

A Department of Health spokeswoman said: "This Government was the first to put in place measures to ensure the NHS isn't abused, and as this report finds, we are making very good progress - the amount of income recovered has already more than trebled in three years to £289 million.

"We consulted earlier this year on extending the charging of migrants and visitors using the NHS to other areas of healthcare.

"We will set out further steps in due course to ensure we deliver on our objective to recover £500 million a year by the middle of this Parliament."

However, head of the NAO Amyas Morse said Trusts still have a long way to go.

He said: "Hospital trusts remain some way from complying in full with the requirement to charge and recover the cost of treating overseas visitors.

"In the past two years, the amounts charged and amounts actually recovered have increased. Much of this increase is the result of changes to the charging rules.

"If current trends continue and the charging rules remain the same, the department will not achieve its ambition of recovering up to £500 million of overseas visitor income a year by 2017-18 and faces a potential shortfall in the region of £150 million."