Five police officers and a member of civilian staff involved in Operation Weeting, the Metropolitan Police's phone-hacking probe, have faced misconduct allegations, it emerged today.
The group included two detective constables working on the investigation against whom claims were upheld.
One resigned after an allegation of "other neglect or failure of duty" was upheld, and the other received "management advice" in December 2011 and was no longer working on the inquiry, the force said.
The member of police staff received a final written warning in June last year after being found guilty of discreditable conduct, and is also no longer attached to the operation.
Details of the allegations were revealed after a freedom of information request by The Sun newspaper.
They include another detective constable who is suspended after being arrested "for a matter allegedly related to Operation Weeting".
The matter was a criminal investigation but was now being dealt with as a misconduct issue.
A fourth officer is under investigation over claims linked to a previous inquiry unconnected with phone hacking, and the fifth, a detective constable, received management action in July last year over unrelated claims.
Management action is an internal process and is not a formal misconduct finding.
The Metropolitan Police also revealed that a detective constable working on Operation Elveden, the inquiry into alleged corrupt payments to public officials, received management action in June 2011.
This was over a previous investigation in which the officer gave personal details of a suspect to a victim.
Operations Weeting and Elveden are being run alongside Operation Tuleta, an inquiry into computer hacking and other alleged privacy breaches.
A Scotland Yard spokeswoman said: "Many of the misconduct matters involving staff from Operations Weeting, Elveden and Tuleta took place prior to the officers being posted to these operations.
"The MPS takes all matters of misconduct and professional behaviour seriously. It should, however, be noted that the majority of these cases were at the less serious end of the scale and that the sanction of management action is not a formal misconduct outcome and is considered to be part of the normal managerial responsibility of managers in the police service."
The detective constable currently suspended from Operation Weeting was accused of passing information to journalists, but the Crown Prosecution Service said last May that no criminal charges would be brought.