NHS trusts are paying three times the market price for systems under the failed National Programme for IT (NPfIT), according to an MP on the Public Accounts Committee.
While NPfIT was supposed to deliver complex but standardised systems at an affordable price, hospitals are spending much more with suppliers BT and CSC than by buying elsewhere, said Richard Bacon MP, an expert on the programme.
Bacon took the figures from written parliamentary answers, National Audit Office reports, and the suppliers' regulatory filings.
North Bristol NHS Trust has paid BT £29 million over seven years for the Cerner Millennium patient administration system.
Bacon said this was "more than three times" the price paid by University Hospitals Bristol Foundation Trust, which did so outside the programme for a reported £8.2 million.
Morecambe Bay NHS trust, served by CSC, was also overpaying. It has spent £6.2 million on the programme including the iSoft Lorenzo equivalent patient system.
Typical internal trust costs of deploying of a non-NPfIT system, excluding the cost of the system itself but including training, project management and additional corporate reporting tools, Bacon said, "can be about £2 million".
The news comes as it emerged that CSC is expecting to be paid £2 billion more for its work on the programme, costing each UK income taxpayer £77. CSC has been so heavily criticised for its performance that government committees have advised ministers to consider not giving it any more public sector contracts.
CSC has also insisted the government is unable to legally cancel its contract at will.
The Department of Health, the Cabinet Office and CSC have not provided any justification for the expenditure.
BT said its prices were "independently verified" and represented "value for money".
Bacon, a vocal critic of the programme, said it was time the government ensured trusts are fully aware of the ongoing costs of NPfIT implementations and associated services.
He added that CSC should not be given a contract that commits to a specific number of systems, "so that trusts will not be put under pressure" to buy software in order to fulfil the supplier agreements.