The Police and Crime Commissioner has said police officers who allowed a jailed supergrass to visit a brothel, take drugs and have sex with a female police officer should be held to account.
Mark Burns-Williamson is to meet with MPs to discuss supergrass Karl Chapman and has called for an overhaul of the Independent Police Complaints Commission (IPCC).
In 1996 Karl Chapman testified against Paul Maxwell and his brother, Daniel Mansell, who spent 11 years behind bars for the murder of Joe Smales and robbery of his brother Bert in their Stanley home.
In 2011 the Supreme Court quashed the verdicts and ordered a retrial for Maxwell - who was later jailed for life after admitting murder and robbery - because of police misconduct in relation to Chapman.
The case featured heavily on the pages of the Express, and subsequently the IPCC supervised a review by West Yorkshire Police into the case.
At least ten police officers were believed to have been prepared for potential prosecution or disciplinary procedures but no action has been taken.
Mr Burns-Williamson said internal investigations had identified “systematic failings” by police.
He said: “The case continues to be considered, important lessons have been learned and such a situation could not re-occur.
“The next steps in this very complex case require careful consideration, not least in conjunction with the new Chief Constable Mark Gilmore.
“I will also be lobbying the government for a long overdue, much more efficient and effective complaints authority with the right capacity and capability to investigate cases such as this one and hold the police to account in the public interest and for additional powers for.”
Temporary Chief Constable John Parkinson said a number of recommendations have been taken forward since the review was carried out.