Former Chief Superintendent Colin Andrews - who had held senior roles supervising the investigation of cases involving sexual offences and domestic violence - was also convicted of stalking.
He bombarded her with texts and phone calls ranging from “nice and apologetic” to “downright nasty and threatening to ruin her life or career”, even turning up at her house late at night to stare through the window.
However he was cleared by the jury of another count of assault, assault occasioning actual bodily harm and rape following the trial at Manchester Crown Court.
The Independent Police Complaints Commission said last night there could be “no place in policing for those who abuse their positions or influence to carry out criminal acts of this kind.”
Andrews, 59, who retired from Humberside Police in 2012 but later rejoined in a civilian role as a manager in the force’s criminal justice unit, is currently suspended and now faces internal conduct proceedings.
Police and crime commissioner Matthew Grove said: “The public can be reassured that no one, even a highly decorated former police officer, is above the law.”
The court was told Andrews, was a Jekyll and Hyde character, who could be charming, but also jealous and controlling and “utterly self-deluded”.
It heard that the women in the case had been concerned about taking formal action against such a well connected figure in the local criminal justic system.
Andrews had been accused of stalking one woman to an extent which made her life intolerable, and ignoring the bluntest of warnings about his behaviour. He called her 89 times in one day.
By August 2013 matters came to a head when he was seen acting aggressively towards a woman in Park Grove, Hull, by passerby Owen Phillips who called police on his mobile only to be verbally abused and slapped in the face by Andrews.
The final count of witness intimidation arose from the same incident after he sent a text to the woman suggesting embarrassing features of her life might be exposed. The prosecution said it was “straightforward blackmail.”
IPCC Commissioner Kathryn Stone said: “I have been reassured by the Chief Constable that the wider organisational matters indentified during this investigation are being addressed so that the communities Humberside Police serve can have increased confidence in their police force. The IPCC will now make its misconduct recommendations to Humberside Police and make arrangements for the findings from the investigation to be published at a later date.”
Andrews will be sentenced on March 13.