The former head of Operation Yewtree has admitted police "got some things wrong" during its investigation into child sexual abuse in the wake of the Jimmy Savile scandal.
Peter Spindler, a retired Metropolitan Police commander, said some detectives who worked with the probe "didn't have the skills and knowledge" needed and the inquiry was not set up quickly enough.
Mr Spindler was speaking at the NSPCC's headquarters in London during a debate on whether non-recent sexual abuse investigations had descended into "media witch-hunts".
Mr Spindler said the media had a "ferocious appetite" but insisted the Metropolitan Police did not release the names of suspects before they were charged.
He said 30,000 victims who had yet to report abuse were expected to come forward to the Goddard inquiry, the independent investigation into child sexual abuse.
Operation Hydrant, set up by the National Police Chiefs' Council to investigate child sexual abuse allegations, had the names of more than 2,000 suspects and 670 institutions where abuse was said to have happened, he said.
"These people can't all be making it up, they haven't all got it wrong," Mr Spindler said.
Around 70 complaints were being investigated by the Independent Police Complaints Commission in which victims said they were not taken seriously or crimes were covered up, he added.
Operation Yewtree was launched in October 2012 to investigate alleged abuse by Savile and others.