NHS figures showing there were no ambulance delays at the Norfolk and Norwich University Hospital over winter are inaccurate.
Delays with ambulances handing over patients have long caused problems at the hospital and have meant lengthy waits for those calling 999.
Data on how many times ambulance crews were forced to wait outside A&E departments because they were too busy to take new patients is collected by the East of England Ambulance Service Trust (EEAST) every day from November 27 to the end of February to give health chiefs an accurate view of pressures.
These figures, which record how many times crews had to wait between 30 and 60 minutes and more than 60 minutes to handover their patient, are given by the EEAST to individual hospitals, which then report this to the NHS nationally.
But the latest data for the Norfolk and Norwich Hospital (NNUH) shows that between December 26, 2017 and January 21 this year there were no delays of any kind at the NNUH.
This was despite there being numerous reports of long waits, including in the death of Brian Havard, who was held in an ambulance outside A&E for four and a half hours on January 9.
The NNUH said original data had shown zero delays because of a change in how the ambulance service measured its response times in October, and the data 'could not be verified' or integrated in their own systems.
But the introduction of the new response times, known as the Ambulance Response Programme, was concerned with how quickly crews reached patients following a 999 call, not their arrival at a hospital.
And the James Paget Hospital (JPUH) in Gorleston and the Queen Elizabeth Hospital (QEH) both reported their statistics during the period.
The NNUH said that because the data could not be verified they submitted a 'no data return' between December 26 and January 21.
A spokesman said: 'Unfortunately, upon submission this was misinterpreted as a 'zero' within the data return. If we are not satisfied that the data is accurate for any reason would submit a 'null return' until assurance is gained that the data is correct.'
The spokesman added: 'We were advised on December 12 that the EEAST system resumed normal function which we then had to reintegrate within our own data systems.'
But this did not happen until 40 days later and the hospital did not start reporting the delays again until January 21, with the exception of December 24 and 25 where a spokesman said 'unverified data was submitted for two days'.
EEAST's director of service delivery Kevin Brown said the trust did not recognised the data provided to the NHS over the period.
He said: 'Our crews and their patients have experienced extensive handover delays in Norfolk over the winter period, particularly at the Norfolk and Norwich University Hospital. Our data shows there were handover delays at the NNUH every day in January.'
This newspaper has been asking for the accurate data since Monday but has still not been provided with it.
Separate figures from the ambulance service show its crews lost 1,650 hours waiting to hand over patients at the N&N in January this year. That was less than December but more than January 2017.
North Norfolk MP Norman Lamb, who said last week up to 81 deaths were linked to EEAST delays, urged the NHS to release accurate data as soon as possible.
'The public has a right to know what is going on,' he said. 'The whole idea of publishing data is to make it easier to hold organisations accountable.'
Norwich South MP Clive Lewis said: 'Like so many other people in this city, I am fed up with senior NHS managers using all kinds of technical wheezes to avoid saying what really needs to be said loud and clear, over and over again.
'In the last few weeks, we've had an ambulance trust whistleblower reveal that at least 40 patients died or were harmed due to delays over Christmas and New Year. A senior trust manager has gone on record to say that two-thirds of the ambulance fleet has been parked outside the N&N unable to off-load patients.
'So it simply beggars belief that there were no handover delays at the hospital in the period we're talking about.'
•The graphic above has been updated with the figures which have now been provided to us by the EEAST showing the true extent of ambulance handover delays.
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