Image copyright South Wales Police Image caption Anthony Rees-Thompson has worked for South Wales Police for a decade

A police officer who tried to cheat his way out of a speeding ticket by changing his car number plates, has been jailed for three months.

Det Con Anthony Rees-Thompson, 40, was caught by a speed camera doing 35mph in a 30mph zone in Swansea.

But the South Wales Police officer from Abercrave, Powys, denied it was him and changed his number plates, Cardiff Crown Court heard.

He denied perverting the course of justice but a jury found him guilty.

Judge David Wynn Morgan told Rees-Thompson the offence "strikes at the heart of the criminal justice system".

He said the points system was to punish people who drive badly, and it depended on the honest completion of the relevant forms.

He added: "Yours wasn't a panic reaction - it was a carefully considered and thought out course of action."

The court heard Rees-Thompson had been driving along Fabian Way on his way to buy tickets for an Ospreys rugby match when he was caught speeding in a car belonging to his stepfather, who was away on holiday.

The defendant, who has worked for South Wales Police for 10 years, challenged the fixed penalty notice and was asked to submit photographic proof that it was not the same vehicle.

'Technical error' claim

But the court heard he sent in photographs of the silver Vauxhall Corsa with new plates customised with a blue GB sign and the Welsh flag, bought for £21 online.

The father-of-four then wrote to the speed camera unit saying there had been a technical error or another similar car was using the same registration number.

The jury heard the police officer, a father of four, worked in the covert operations management unit at South Wales Police headquarters in Bridgend.

But the prosecution argued he forgot that his car was being filmed every day as he drove it into work.

The jury was shown pictures of the car with its old number plate before the speeding offence and the new one allegedly fitted by Rees-Thompson.

The court was also told that Rees-Thompson pretended to be his stepfather when he wrote to the speed camera unit trying to avoid a fine and three points on his licence.

He denied perverting the course of justice during his trial claiming he changed the plates because they were damaged.

Rees-Thompson is set to lose his job and will face a "fast track" gross misconduct disciplinary hearing following his sentence.