The former head of the police watchdog has denied getting his dates wrong over allegations he molested a 14-year-old girl in a toilet while working as a lifeguard.

Michael Lockwood, 65, faces 17 charges – for three rapes and 14 indecent assaults – relating to two 14-year-old girls some 40 years ago.

At the time, he was in his 20s and worked part-time at a leisure centre near Hull in East Yorkshire where he allegedly met and sexually abused the girls.

One of the alleged victims has claimed Lockwood indecently assaulted her in a male toilet cubicle repeatedly before moving to a storeroom at the leisure centre.

Jurors have heard it became “common knowledge” that the pair would go into the toilet among fellow lifeguards who sang a nursery rhyme about them being “locked in the lavatory”.

Lockwood has admitted having a romantic relationship with the woman, but claimed it did not begin until later, after she was aged 16.

On Tuesday, prosecutor Jonathan Polnay KC challenged his version of events and suggested Lockwood – and not the woman – had got his dates wrong.

Cross-examining, Mr Polnay said: “The period with which (the woman) was 16 and you were working as a lifeguard at the leisure centre is a maximum of five weeks, do you agree?”

Lockwood replied that he continued to use the leisure centre when he came back to Hull on weekends, after he moved to Liverpool.

Mr Polnay went on: “And that five-week period – multiple trips to the toilet and multiple trips to the storeroom, all while you were working as a lifeguard. It couldn’t have happened, could it?”

Lockwood replied: “It may have over that five weeks. I cannot remember. I remember we had a friendship for a long period over time before then. In terms of any sexual intercourse, that did not happen until the next year.”

Mr Polnay said: “You are a man who has had very senior roles. If you are being really honest with this jury when you have got those dates put together do you think, actually, you might be wrong? She’s right and you are wrong?”

Lockwood said: “No (the woman’s) recollection over dates were wrong.”

Mr Polnay said: “I am going to suggest the sexual activity (the woman) described with you at the pool could not possibly have happened in that timescale.”

The defendant disagreed.

Jurors have heard that after allegations against him first emerged, Lockwood resigned from his job as director general of the Independent Office for Police Conduct (IOPC), which is the police complaints watchdog for England and Wales.

Lockwood has pleaded not guilty to eight indecent assaults relating to the woman on dates between August 1979 and August 1981.

The defendant, of Epsom in Surrey, denies three counts of rape and six counts of indecent assault relating to the other complainant between October 1985 and March 1986.

The Old Bailey trial before Mr Justice Bennathan continues.