The number of fraud cases investigated in the NHS has risen by 37% in the last three years amid the economic downturn, official figures have revealed.
Data from the NHS Counter Fraud Service showed the amount of cases of potential fraud detected and probed increased from 351 in 2007/8 to 415 in 2008/9 and 482 in 2009/10.
The value of fraud and unlawful action identified was £4.1m in 2007/8, £16.2 in 2008/9 and £10.9 in 2009/10.
The types of fraud committed varied enormously, the organisation said, but recurrent kinds of fraud related to staff and professionals claiming money for shifts not worked, known as "timesheet fraud" and employees working in unauthorised jobs while on sick leave.
Other categories included patients who might try to avoid paying prescriptions by falsely claiming exemptions or using aliases to obtain drugs; professionals altering prescriptions or creating "ghost patients" and contractors or suppliers attempting to exaggerate records of NHS work.
Allan Carter, head of operations at NHS Counter Fraud Service, told The Times: "Undoubtedly in times of recession people will look to maximise their opportunities. And when you look at the case numbers it might seem that way."
He said the service had recovered more than £65 million to date.
One case investigated related to a former senior NHS manager who doctored invoices totalling more than £200,000 to pay for the running of her stud farm business.
Louise Tomkins, 48, of Faygate, West Sussex, was jailed for two years and nine months in June 2010 at Southwark Crown Court.
The court heard she fraudulently signed off NHS payments running to £201,333.27 to fund the upkeep of thoroughbreds and pay for horse semen, breaching the trust of her employers.