A former police officer who abused his position to have sex with a teenaged crime victim has been banned from duty.
Gareth Roberts, 42, met the victim while on duty for West Yorkshire Police in 2011 and their relationship eventually turned sexual in 2016.
He was found guilty of gross misconduct by a police disciplinary panel.
The Independent Office for Police Conduct (IOPC) said he had abused his role and "crossed a professional boundary".
The watchdog started an independent investigation in March 2018, four years after Mr Roberts moved to the Metropolitan Police.
A two-day hearing was told Mr Roberts had been told not to contact the boy after joining the London force.
The panel heard the PC established a personal relationship with the "vulnerable" victim after he was asked to mentor and provide support to the youngster, who was expected to give evidence at a number of criminal trials.
It concluded he breached professional standards of behaviour for authority, respect and courtesy, and discreditable conduct.
The IOPC said it had gathered evidence from support agency workers who had knowledge of Roberts's relationship with the teenager, and statements from witnesses at both police forces, but its investigation, which ended in September 2020, found nothing to suggest there had been any sexual contact between the pair before the victim turned 18.
IOPC Regional Director Sal Naseem, said: "Police officers abusing their position to form inappropriate relationships for sexual purposes is both hugely damaging to, and also undermines, the public's trust and confidence in policing."
Det Ch Sup Owain Richards, from the Met, said: "Roberts resigned following the investigation and quite rightly so.
"The hearing determined that, had he still been a serving officer, he would have been dismissed. I hope this sends a strong message about the expectations we have of our officers and that behaviour such as this will absolutely not be tolerated."