Victims of disgraced breast surgeon Ian Paterson are still coming forward two years after he was jailed following hundreds of botched operations.
The "sheer volume" of patients giving evidence to an independent inquiry has pushed back a report into his malpractice, an official said.
Paterson is serving a 20-year sentence for 17 counts of wounding with intent.
About 150 patients gave evidence last year and dozens more are understood to have since come forward.
Inquiry secretary Rebecca Chaloner said many of those were cases that were not previously known about.
The report was due this summer but is now expected by the end of the year.
Appeal Court judges, who increased Paterson's 15-year sentence, said victims were left feeling "violated and vulnerable", with his treatment of patients described as "brutal and sustained".
The inquiry, which began in January 2018, is taking evidence from the NHS and private hospitals at which Paterson, from Altrincham in Greater Manchester, worked, the Royal College of Surgeons and the insurance and indemnity industry.
It is understood a number of previously unknown victims have come forward to the inquiry through support groups in the West Midlands.
Ms Chaloner said the process would give victims "a voice" despite the delay.
"It's due to the sheer number of people coming forward," she said.
"We spent the spring and summer of 2018 taking evidence from more than 150 patients, but people are still coming forward - quite a few that weren't a part of anything else (the criminal and civil cases).
"We are pleased as it has given them a voice."
The Department of Health said it wanted to learn lessons from the case and improve care.
It said the scope of the inquiry was likely to consider:
- The responsibility for the quality of care in the independent sector
- Information sharing, reporting of activity and raising concerns between the independent sector and the NHS
- The role of insurers of independent sector healthcare providers, including how data it held about the scope and volume of work carried out by doctors was shared with the sector