A third of police forces are failing to fight child sex exploitation effectively, something the NSPCC condemned as "deeply depressing" in the wake of major, high-profile scandals over the crime.
The charity said this was "remarkable" in light of high profile child grooming cases that were exposed in Rotherham and Rochdale after years of police failure to prevent it.
The finding was made in the latest report on police effectiveness by Her Majesty's Inspectorate of Constabulary, which found police were better at tackling traditional forms of organised crime such as drug dealing rather than "newer" ones such as organised child sex abuse.
"It’s deeply disturbing that at least one in three police forces in England and Wales are still not tackling child sexual exploitation effectively,” a spokesperson for the child protection charity said.
"This seems a remarkable state of affairs considering the high profile trials of grooming gangs in Rotherham, Rochdale and elsewhere which sharply brought into focus the failings of police forces in investigating these crimes and supporting young victims."
The profile of child sex exploitation has risen considerably in recent years after high-profile cases and prosecutions. An independent report concluded at least 1,400 children were victims of abuse between 1997 and 2013 in Rotherham alone.
HMIC found that forces were putting more resources into fighting sexual exploitation - including specialist teams with no other focus - and were providing training to help officers recognise patterns in the often-hidden crime.
But the inspectorate said the forces' implementation of these changes was "patchy" and the initial commitment was not always kept up.
The quality of the new training varied greatly and there was often no evaluation to tell how effective it was.
It said one force was a "cause of concern" while another 13 of the 43 forces in England in Wales "had areas for improvement" over tackling child sexual exploitation.
South Yorkshire Police, which was severely criticised for failing to prevent child sex exploitation in Rotherham for more than a decade, was praised for an initiative in which it trains hotel staff, shop workers and taxi drivers on how to spot the signs of child sexual exploitation.
The NSPCC said it was concerned the police were "lagging behind the offenders" over cyber crime "as child abusers increasingly groom and abuse victims online".
“As more victims of child abuse and exploitation continue to come forward, it’s essential that all police forces are properly trained and equipped to respond to these most horrific of crimes," the NSPCC said.