Hospitals have flouted caps on temporary doctors' pay hundreds of thousands of times in a matter of months, new figures show.
A crackdown on the amount the health service can spend on agency staff wages was introduced in an effort to curb spiralling costs.
NHS Improvement said 241,195 pay cap breaches by hospitals in England took place between July and September last year.
A report from the watchdog recently said employers had to break the limit to win a "bidding war" with neighbouring trusts where there was a limited supply of agency staff in the area.
Millions of pounds are being spent on locum doctors every year, data from the organisation has shown.
This includes an annual cost to the NHS of £7.5 million from just 20 of the most expensive agency doctors, an average of £375,000 each, including one individual charging £363 an hour.
A Freedom of Information request by Sky News this week also found 56 of the 61 hospital trusts who provided data exceeded the average hourly pay cap of £76.10 for locum consultants over the three-month period
"We know that if staff are having to work alongside others who are earning a lot more, that doesn't feel right or fair," NHS Improvement executive medical director Dr Kathy McLean told the broadcaster.
"It's also not good use of taxpayers' money. It should be spent on other aspects of care for patients."
Hopes that the spending restriction would lure temporary staff into full-time positions was branded "largely unsuccessful" last month by the National Institute of Economic and Social Research.
Figures from February showed there had been a £505 million improvement in spending on agency staff over the previous nine months.
Spending on locum and agency staff in December last year was £228 million - 24% lower than in December 2015.
In 2015, health officials announced a package of measures to clamp down on agency spending, including caps on the hourly rates, after it emerged that the NHS in England spent more than £3 billion on agency workers in 2014/15.
NHS Improvement said £300 million a year could be saved if all medical locums charged rates within the set price cap.
A new national target has been set to reduce medical agency expenditure by £150 million in 2017/18.