Police officers are using their position for sexual advantage and indulging in steroid abuse, which leaves them open to corruption.
Force chiefs admitted that the abuse of power for sexual favours was one of the most common acts of corruption. The admission follows revelations that dozens of officers have been disciplined for inappropriate sexual behaviour.
An independent assessment of police integrity, published by the Association of Chief Police Officers, also highlighted concerns about the use of steroids.
Mike Cunningham, the Chief Constable of Staffordshire Police, said that what would happen was that officers would go to gyms and begin to dabble in steroids and then the relationships they formed while using steroids became corrupt and corrosive. "There is good evidence of officers getting way out of their depth with serious criminals who they are beholden to," he said.
Mr Cunningham added that the professional standards department in every force across England and Wales were investigating allegations of steroid abuse.
Andy Trotter, the Chief Constable of British Transport Police, said that exercise trends were a factor. "A lot of police officers keep themselves very, very fit these days," he said.
Chief constables will discuss on Friday how to tackle allegations of corruption after an independent review by Transparency International concluded that forces should take a "zero tolerance" approach.
The report also raised concerns that the creation of police and crime commissioners has left gaps in governance and could raise the risk of corruption.
Plans to be considered in a drive to reduce corruption include making details of gross misconduct hearings public and revealing details of chief constables' pay packets and perks. Ethics committees could be set up to monitor each force, independently of the police and crime commissioner.
Mr Cunningham revealed that concerns about officers misusing their position, including for sexual advantage, ranked third in the list of corruption threats. The top two threats were misuse of information systems and inappropriate relationships.
It emerged last year that more than 50 officers had been convicted or disciplined for a range of offences, including rape, sexual assault and misconduct in public office relating to inappropriate sexual behaviour.