The medical director of NHS England has disclosed that up to one in seven hospital procedures are unnecessary, it has been reported.
Sir Bruce Keogh is said to have described waste in the health service as "profligate" and called for it to be reduced.
According to The Sunday Telegraph, the former heart surgeon estimated that up to 15% of the NHS budget is spent on treatments that should not take place.
The newspaper reported that analysis by his staff showed unnecessary operations and medication cost the health service up to £1.8 billion a year.
Figures suggested that one in seven hysterectomies were unnecessary - equivalent to about 6,600 procedures a year - and in as many as one in five cases patients are being prescribed antibiotics needlessly.
Speaking at a conference of senior doctors and managers, Sir Bruce said: "We know a substantial proportion of expenditure in our healthcare system and in other Western healthcare systems - 10,15 per cent - is due to over use of treatment.
"We also have a massive duty to look into all our organisations and to look into the waste.
"The waste is profligate in our system. I don't think we should be ashamed of pointing that out and certainly we shouldn't be ashamed of dealing with it."
An NHS England spokesman said: "NHS England has been working as a partner with the Academy of Royal Medical Colleges to join the international campaign of Choosing Wisely to establish which interventions do not help patients in the care of their condition.
"There is much evidence that there is significant overuse of some treatments such as antibiotics but when medicines are needed it's important that patients receive them."