The Labour MP Ashok Kumar said that Operation Lancet had led to the "crazy" situation where hard-working detectives were suspended on the word of criminals whom they helped to put behind bars.
The inquiry was set up in response to allegations about the Cleveland police's handling of an incident in January last year when a girl aged 12 was drugged and raped.
Operation Lancet is being conducted by officers separate from Cleveland police, under the supervision of the Police Complaints Authority (PCA). It has led to 560 disciplinary notices being issued to 60 officers.
But Mr Kumar, who represents Middlesbrough South and Cleveland East, told the Commons that "Lancet is being used as an excuse within the Cleveland force for settling old scores and petty jealousies".
Mr Kumar said that the operation was showing "alarming similarities" to the PCA investigation into allegations against police officers on Humberside, which took six years to complete, cost pounds 4m and ended without any disciplinary or criminal charge being brought.
"It seems the PCA is able to operate with an open timespan, an open remit and an open chequebook," Mr Kumar said.
The PCA said last night: "Parliament does not give us the option of dropping investigations. It is imperative that when serious allegations are made they are thoroughly investigated, because otherwise faith in the police service will be affected."Reuse content