THAMES Valley Police Chief Constable Sara Thornton was last night refusing to talk about her relationship with a subordinate officer.

The Mail on Sunday reported that Ms Thornton and Supt Gilbert Houalla attended two state banquets at Windsor Castle hosted by The Queen and Duke of Edinburgh.

Ms Thornton, 48, also claimed back the £135 cost of hiring Supt Houalla’s dinner suit.

It is understood Supt Houalla has been separated from his wife for 10 years. His relationship with Ms Thornton has never been kept secret.

However it was unclear last night if they were still involved with each other.

Ms Thornton refused to comment whether the story affected her position commanding Thames Valley.

Force spokesman Victoria Bartlett said: “The Chief Constable is declining to comment on what is a private matter.”

Supt Houalla, 50, has previously served as a Detective Chief Inspector at Oxford’s St Aldate’s police station and an inspector in Thame.

He is now the area commander for the Wycombe police district.