GPs have been over-paid millions of pounds for patients who have moved practice, died or been forced to leave the country, according to a new report.
A one-year review by the Audit Commission identified more than 95,000 patients who needed removing from GP lists in England and Wales.
They included almost 30,000 patients who had moved to another practice (31% of the total), more than 32,000 who had died years before (34%) and almost 10,000 failed asylum seekers (10%).
Nearly 20,000 patients (21%) were also removed from lists after investigators found high numbers of people registered at the same property.
While it would not be unusual for 50 patients to be registered at a nursing home, 20 patients registered in one house would suggest inaccurate GP lists, they said.
Of those patients who had died but were still on GP lists at the time of the review in 2009/10, 157 died before 1980.
They included one patient whose GP continued to be paid for their care for around 40 years despite the fact they died in 1969. A further 335 patients had been on lists for up to 30 years despite dying between 1980 and 1990, while another 429 had died between 1990 and 2000.
Inaccurate GP lists can mean some practices receive more than their fair share of funding, while others miss out.
When patients move to another practice, failing to remove them from an existing list can also mean two GPs being paid for one patient's care.
GP practices are paid £64.59 for each patient on their list. The report - known as the National Duplicate Registration Initiative - said the removal of more than 95,000 "ghost patients" meant the NHS had been able to save more than £6.1 million in one year.