The NHS has paid more than £17 million in compensation for victims of rogue surgeon Ian Paterson.
NHS Resolution said, as of July 31, it had received 277 claims involving Paterson's NHS practice and paid £17,411,639 in total on those cases.
The figure, first reported in the Health Service Journal, may increase as private patients have launched a legal bid against the Heart of England NHS Foundation Trust, private health provider Spire Healthcare and Paterson.
Spire said the Trust has to "explain its delay in informing the private sector of its concerns, allowing Ian Paterson to go on treating (and harming) private patients".
Last week the surgeon, who carried out unnecessary breast operations leaving victims scared and disfigured, had five years added to his jail sentence for his crimes.
Court of Appeal judges in London declared a "just" sentence of 20 years should replace the "unduly lenient" 15 years he was given in May.
Paterson, 59, from Altrincham, Greater Manchester, was convicted by a jury at Nottingham Crown Court of 17 counts of wounding with intent and three counts of unlawful wounding against 10 private patients.
The case against Heart of England NHS Foundation Trust, private health provider Spire Healthcare and Paterson will reach the High Court later this year.
A Spire spokesman said: "The Ian Paterson case is unprecedented in size and in terms of the novel issues raised against the NHS and against the private healthcare sector.
"Although the current litigation has at its heart the actions of Ian Paterson, a surgeon who deceived and criminally assaulted his patients, the claimants have also brought claims against his employer, the Heart of England NHS Foundation Trust (HEFT), and against Spire, which was not his employer but was where he conducted much of his private practice.
"Whilst the claims against Ian Paterson appear to be clear cut, the claims against Spire and the NHS are significantly more complex.
"HEFT was criticised by Sir Ian Kennedy in his 2013 review of Ian Paterson's activity at HEFT, and it admits that it should have stopped him performing breast surgery from late 2004.
"But it has difficult questions to answer about its knowledge of Ian Paterson's activity before that time.
"HEFT also has to explain its delay in informing the private sector of its concerns, allowing Ian Paterson to go on treating (and harming) private patients.
"This trial of lead cases, which is due to take place in the autumn, is a fair and efficient way to determine the issues and secure compensation and justice for all the claimants."
A HEFT spokesman told the HSJ that the trial would determine if the trust had a legal duty of care for private patients who were cared for independently of the NHS.
He added: "Spire is alleging that the trust is responsible for Mr Paterson's private practice and as such should be responsible for compensation to the as yet unsettled claims involving non-NHS patients.
"Spire argues that its role was essentially to provide facilities from which seemingly competent doctors could practise.
"Spire also argues that while it had in place some clinical governance safeguards, it relied on the NHS, as the primary employer of such clinicians, to tell it whether doctors were competent or whether there were patient safety concerns.
"If this argument succeeds, it will significantly increase the scope of the NHS's liability to patients, some of whom it will have no relevant prior knowledge of.
"This attempt to wholly extend the duty of care owed by the NHS will be robustly defended."