Greater Manchester Police Chief Constable Ian Hopkins has apologised to the children abused "in plain sight" by the grooming gangs his officers failed to bring to justice.
He spoke after a damning report revealed senior Greater Manchester Police (GMP) officers and senior officials at Manchester City Council, looking after many of the victims in care, were aware but did nothing to act.
A police drive called Operation Augusta to tackle street grooming by gangs of Asian males preying on vulnerable teenage girls in Manchester was launched then abruptly closed down by senior officers in 2004.
His officers are now trying to track down paedophiles 15 years after their victims first told of the abuse.
Malcolm Newsam CBE, a renowned childcare expert, and Gary Ridgeway, a former detective superintendent with Cambridgeshire Police, authors of the report into Operation Augusta, concluded: "The authorities knew that many were being subjected to the most profound abuse and exploitation but did not protect them from the perpetrators.
"This is a depressingly familiar picture and has been seen in many other towns and cities across the country."
Mr Hopkins, who became head of the force in 2015, said: "On behalf of Greater Manchester Police, I want to apologise to all those vulnerable children who were let down in 2004 by police not thoroughly investigating the offences that had been committed against them.
"I want to say that I am personally disgusted that these children were not cared for and by the awful abuse that they suffered."
GMP has re-launched the grooming investigation, now called Operation Green Jacket, and identified 53 potential victims, 48 of them in council care at the time with "viable lines of enquiry" to investigate regarding 38 victims.
His force also joins South Yorkshire Police following the scandal in Rotherham, in being investigated by watchdogs the Independent Office for Police Conduct (IOPC) over their botched street grooming investigations.
Assistant Chief Constable Mabs Hussain of GMP told the PA news agency: "The victims have been incredibly upset.
"They have been very upset about the abuse they have suffered. They are incredibly hurt by how they were let down and nobody listened to what they had to say.
"They talk about having to re-live the nightmare.
"We clearly failed these young people and our focus today is making sure they get the justice they were denied in 2004, 2005."
Mr Hussein said he expected police will bring charges against some suspects but declined to apologise directly to Maggie Oliver, the former GMP detective who turned whistleblower over Operation Augusta.
He said: "Our apology is to the victims and I'm grateful to all those individuals who have raised awareness of these horrendous offences in our communities."