All hospital units used to "contain" vulnerable people should be closed, a Norfolk MP told the Commons.

Jerome Mayhew, Conservative MP for Broadland, told MPs over 2,000 patients remain in assessment and treatment units despite the coalition government's vow to close them by 2014.

Mr Mayhew said that the "most monumental conflict of interests" exists for private hospitals as there is a "huge commercial incentive" to keep patients inside.

MPs heard each patient comes with a "fat cheque" amounting to several thousand pounds a month, thereby limiting the desire of the units to treat and release them.

Mr Mayhew's plea came against the backdrop of an independent report into the deaths of people at Cawston Park Hospital near Aylsham - a private hospital for people with learning disabilities.

The Broadland MP raised findings from the report, which examined the deaths of Ben King, 32, Nicholas Briant, 33, and 36-year-old Joanna Bailey.

Their relatives described "indifferent and harmful hospital practices" while the report made reference to "excessive use of restraint and seclusion by unqualified staff" and a "high tolerance of inactivity".

"Unless this hospital and similar units cease to receive public money, such lethal outcomes will persist," the report said.

Cawston Park closed earlier this year.

Mr Mayhew, speaking in a House of Commons adjournment debate, highlighted the 2012 coalition government pledge to act but told MPs: "It didn't happen.

"Today, in 2021, more than 2,000 patients are still contained in assessment and treatment units - and I use that word advisedly - they are contained."

He asked health minister Gillian Keegan to, on behalf of the Government, recommit to the "needed closure of all assessment and treatment units".

Mr Mayhew said: "Why do we need to do it?

"Well, there's the most monumental conflict of interests for these private hospitals.

"Beyond being merely inhumane, there is a huge commercial incentive to maintain residency because each of these patients came with a fat cheque - £26,000-a-month per patient - and you can see where the conflict lies.

"You can see why one family member when they went to Cawston Park Hospital was handed a piece of paper by another person.

"On it was the address of a firm of solicitors and a statement where she said: 'Once people are in Cawston Park Hospital, you can't get them out.'

"Patients didn't leave Cawston Park Hospital and it's structural.

"If you pay a hospital £26,000-a-month in order to assess and treat, is it not surprising that they don't release them?"

North West Norfolk Conservative MP James Wild highlighted words from Mr King's mother, Gina Egmore.

MPs heard she said: "If you ill-treated an animal, you get put in prison. But people ill-treated my son and they're still free."

Mr Wild added: "Isn't that situation completely unacceptable and the police and the authorities should look again at all leads and all evidence and review that, and hold those people to account?"

Mr Mayhew replied: "Management teams and owners need to fear prison personally as a response to a failure in the culture."

He said he plans to meet with the Law Commission in October to highlight the need for people who run such hospitals to "fear for personal prosecution".

Care minister Gillian Keegan said the Department of Health and Social Care is working with the NHS, local government and the Care Quality Commission to "identify unacceptable care with urgency" and take "robust action immediately".

She added: "I appreciate that everyone listening will want assurances that anyone with a learning disability and any autistic person in one of those hospitals - you mentioned 2,000 - is safe.

"NHS England reviews of each individual person's care arrangements will ensure that there is a clear care plan in place with a clear path to discharge.

"This must not happen again in that way where there's no clear paths to discharge."