The police watchdog has said 29 serving and former police officers are being investigated over one force’s handling of child abuse cases.
The Independent Police Complaints Commission probe relates to the handling of 49 child abuse inquiries between 2011 and 2015 reported to Essex Police.
Six of the officers are also facing a criminal investigation for alleged offences including misconduct in public office and perverting the course of justice.
Essex Police said it had already taken “a number of immediate actions to put things right”.
When it first announced its investigation into the team covering the north of Essex in February it said it was investigating 12 officers.
The case has more than doubled in scope since the IPCC’s enquiries began.
This now spans 25 serving officers and four former officers - all of whom are below the rank of assistant chief constable.
The group have all been served notices which advises them that their conduct is subject to investigation.
Of the notices 22 allege gross misconduct and seven relate to alleged misconduct matters.
These include failing to make reasonable enquiries and progress investigations, failing to address victim safeguarding and concerns regarding honesty and integrity issues in relation to how some investigations were carried out.
Essex Police said two officers have been suspended and most of the remainder moved to different areas of police work.
Deputy Chief Constable Derek Benson said: “These investigations relate to issues we identified and referred to the IPCC.
“We took a number of immediate actions to put things right and will work with the IPCC to identify where further improvements need to be made.
“We are working closely with partner agencies and children’s charities to ensure the force gets expert, independent advice, and the changes we have made to the way we investigate child abuse cases mean that our investigations will be of the highest standards possible.
“There is no more important issue to Essex Police than protecting children.”