Northern Ireland's police chief has insisted that a probe into alleged misconduct in public office will not find any wrongdoing.
George Hamilton and a number of other senior Police Service of Northern Ireland officers are subject to the investigation by the Police Ombudsman.
The claims relate to how the PSNI handled an inquiry into the awarding of a contract to supply vehicles to the force.
Mr Hamilton said he is "absolutely confident that there will not be misconduct established".
And he insisted he has no intention of stepping aside while the probe is ongoing.
Speaking to reporters at an Anti-Slavery Day event in Belfast, he said: "I'm confident in my ability and I have the passion to keep doing this job.
"I've got every confidence that the Ombudsman will be able to get on with his job and to investigate the complaints that have been made."
Former West Yorkshire chief constable Mark Gilmore, a former PSNI officer, and retired PSNI assistant chief constable Duncan McCausland were among nine people interviewed by detectives in the 2014 investigation into bribery and misconduct in public office in relation to the vehicles supply contract.
No charges were ultimately brought against any of the men - all of whom denied any wrongdoing.
Mr Hamilton, current deputy chief constable Drew Harris and current assistant chief constable Mark Hamilton are all now being investigated by Ombudsman Michael Maguire.
A number of other less senior officers are also under investigation.
Dr Maguire has received complaints from a number of those investigated in the vehicle contracts probe in 2014, including Mr McCausland and Mr Gilmore.
It is understood the claims include allegations that police documents were altered.
Mr Hamilton said however: "I'm absolutely confident that there will not be misconduct established.
"People who made these complaints are entitled to make them and I'd encourage them to have the confidence that I have in the Police Ombudsman and allow him to get on with his job."
He added: "We'll allow the Ombudsman to do his job and we'll co-operate fully with that and let's see where the evidence takes the Ombudsman because I'm confident that the outcome for us, the senior officers which have had these complaints made against them, will be a positive one."
Earlier the PSNI issued a lengthy statement denying any wrongdoing.
"PSNI can confirm that a number of senior officers, including the chief constable and deputy chief constable, have been informed of complaints made against them by former senior PSNI officers," said a spokeswoman.
"The complaints relate to allegations of misconduct by senior police during a criminal investigation by the PSNI into the two complainants, former senior colleagues, during 2014.
"PSNI acknowledges and supports the need for the Office of the Police Ombudsman to investigate these allegations and all officers are co-operating fully with the investigation.
"The chief constable, deputy chief constable and other officers completely refute the allegations made against them and are strongly of the view that these complex investigations into the complainants were conducted with professionalism and integrity. This position has been fully outlined in the officers' initial response to Oponi (Office of Police Ombudsman for Northern Ireland).
"Whilst ordinarily the Police Service would limit its responses on matters where it is under investigation, this case has particular and unusual aspects to it.
"This case has been the subject of recent speculative press and media coverage which has the potential to negatively impact on public confidence in policing.
"We have full confidence in the Oponi to complete a thorough investigation and we trust that they are left to do so without ongoing public commentary."
The Ombudsman's Office said its investigation would be treated as a "critical incident".
"The Police Ombudsman's Office has begun an investigation into concerns about the way in which the PSNI conducted an investigation into allegations of bribery and misconduct in public office in 2014," said a spokesman.
"The Office is investigating allegations of criminality and misconduct in how this investigation was undertaken by police.
"It has not named the police officers under investigation, but has confirmed that they include a range of officers, including those above the rank of Chief Superintendent.
"The Police Ombudsman has declared the matter to be a 'critical incident' - an issue the outcome of which could have a significant impact on the person making the complaint, on the police or on the wider community.
"A team has been set up to look into these matters. It includes six investigators and has access to external legal advice.
"Given that some of the officers are above the level of Chief Superintendent, the Policing Board (the PSNI's independent oversight body) has been notified.
"The Office has not recommended the suspension of any of the police officers concerned."
Mr Hamilton was appointed chief constable in May 2014 - a month before the investigation into the vehicle contracts became public.
The new Ombudsman's probe, which was first reported by BBC NI, is expected to extend well into 2018.
Mr Gilmore was suspended from his job in West Yorkshire in the wake of controversy.
He retired two years later having never returned to duty.
At the time of his initial suspension in June 2014, Mr Gilmore, who attended a police interview in Belfast voluntarily, insisted he had always acted with honesty and integrity.
Sinn Fein's Gerry Kelly said the Ombudsman investigation is a "matter of huge concern to the public".
The former Policing Board member said that, while the Ombudsman has not recommended the suspension of the officers, that decision should be kept under review.
He added: "No-one is above the law and every citizen is equal under the law. The investigation should be thorough and carried out with impartiality."