Row over police probe cost.
It was confirmed this week that a team led by Warwickshire's Chief Constable Keith Birstow is to probe Cleveland Police Authority. The probe was instigated by Her Majesty's Inspectorate of Constabulary.
North Yorkshire Police officers, led by detective Chief Superintendent Richard Mann are forming the investigation team.
The team is carrying out a criminal investigation into a number of people with current or past associations with the Cleveland Police Authority.
It follows initial inquiries into the manner in which some individuals within the authority might have conducted some of its business and initial advice from the Crown Prosecution Service has been sought.
A Warwickshire Police spokesman confirmed Cleveland Police would pay for the cost of the inquiry, which is expected to take a significant amount of time.
He added: "In terms of how long will the investigation take - it will be lengthy - it could last for many months."
The last major investigation into police-related matters in Cleveland was Operation Lancet, which was launched in 1997 into alleged malpractice in Middlesbrough CID. The inquiry lasted almost five years and cost an estimated pounds 8m.
In a statement today Cleveland Police Authority said: "We are aware it is being suggested that the costs of the investigation, which was instigated by Her Majesty's Inspectorate of Constabulary and is being led by the Chief Constable of Warwickshire, will be met by Cleveland Police.
"The authority is concerned at this suggestion, given that it was not involved in the decision to instigate the investigation, nor does it have involvement in its conduct, including its duration and costs."