Mental health assessments pay row
NHS England has apologised for delays in paying psychiatrists who carry out assessments to detain people forcibly under the Mental Health Act.
One senior psychiatrist told the BBC he had not been paid for the best part of a year.
NHS England said there had been "some issues in the first financial year of the new NHS commissioning system", and that it was "unacceptable that any service provider should have to wait for payment".
The dispute over fees comes as use of the sectioning and detention powers under the Mental Health Act in England reaches an all-time high. It was used more than 50,000 times in 2012-13.
Dr Ali al-Allaq is a psychiatrist who works in London. He says he is owed tens of thousands of pounds for Mental Health Act assessments he has conducted in north London.
He is known as a section 12 doctor - approved under the Mental Health Act to carry out the assessments which can result in people being forcibly detained.
He says he and some of his colleagues are now refusing to go out at night and see patients - which he believes could increase the likelihood of people needing to be sectioned.
In one case, Dr al-Allaq assessed and detained a man under the Mental Health Act who had been kept in a police cell for 12 hours because no psychiatrist was prepared to assess him during the night.
"He was extremely agitated and angry and some of this behaviour that we see from people in crisis is due to the environment they're held in.
"It might be that the main reason they're detained [under the Mental Health Act] is that they've been kept in that room for a long time and that's clearly reflected in the fact that some of those people end up being discharged within one or two days of their admission to hospital."
He added that he was owed "a lot of money - I'm not sure if I will get any of it and as a result I'm seriously thinking about changing what I do."
Dr al-Allaq mainly works for Haringey clinical commissioning group and it admits there have been problems. In a statement, it said: "This is not an issue that is unique to Haringey and we are working closely with NHS England to resolve it as soon as possible."
A spokesperson for NHS England said: "This is a vital service and we apologise to those affected by late payment... Payment structures were unclear for some services in some areas.
"It is unacceptable that any service provider should have to wait for payment, and NHS England, through its area teams, is working together with clinical commissioning groups to ensure that all services are commissioned properly.
"We are working to ensure all payment structures are clear for 2014-15, and we are pleased to note that psychiatrists in Enfield and Haringey have been given assurances that they will receive payment in full within the next week."
5 Live Investigates spoke to other doctors who have not been paid since last April.
The revelations over the row over fees emerged during a wider BBC investigation into the pressures on mental health services in England.
Paul Farmer, chief executive of mental health charity Mind said: "We're beginning to see the warning signs of an emerging crisis in access to care.
"We know that up and down the country there are increasing signs of services being diminished and threatened as a result of a combination of an increase in demand and also a potential reduction in funding," he added.
One concern is the ease with which patients and their families can access appropriate services.
Daniel Murphy, 28, died after falling from a road bridge in Shrewsbury, soon after he'd walked out of a hospital where he'd been left on a general ward. The mental health crisis team had told his GP to send him to hospital following a mental health breakdown during the day.
His mother, Jane, said: "I took him to what I thought was a place of safety but unfortunately it wasn't because there's no out-of-hours psychiatric care on a Sunday evening. I didn't realise he would have to wait until opening hours."
The South Staffordshire and Shropshire Healthcare Trust admitted he should have been assessed at home or in the hospital's A&E. The trust has said it has issued new guidance to ensure the response to calls is appropriate.
The full report was broadcast on 5 live Investigates on Sunday, 2 March on BBC 5 live.