Richard Brunstrom has been accused of an 'obsession' with speeding drivers

The Sun claimed its reporter had clocked Kate Brunstrom doing 69 mph in a 50 mph zone in Colwyn Bay.

Journalists from the tabloid newspaper were trying to catch Kate Brunstrom's father Richard Brunstrom breaking the speeding laws after his force's high profile crackdown on speeding provoked severe criticism.

It began earlier this year when Mr Brunstrom compared a 71-year-old driver who had been speeding to a "17 year old yob" after the pensioner complained about the fine he had to pay.

Mr Brunstrom had also described speeding motorists as "anti-social" and "criminals" - leading to accusations that he was "obsessed" with speeding motorists at the expense of fighting crime.

A Sun reporter had set out to catch Mr Brunstrom speeding

In August the newspaper published pictures of the Brunstom family's Ford Focus which it alleged was doing nearly 20 miles per hour over the limit on the A55 near Llandudno Junction.

It went on to claim it had used the same type of speed gun as the police themselves use and forwarded its "evidence" to North Wales Police who in turn passed it onto the Crown Prosecution Service (CPS).

But on Thursday it emerged that the CPS had said that Kate Brunstrom will not be prosecuted, as the speed gun was not an approved device and that The Sun's reporter was not trained in using it as a police officer would be.

The CPS called in colleagues from outside Wales to deal with the case, and has stressed it was dealt with in the same way as any other motorist.

In the past, Mr Brunstrom has defended his tough stance on speeding motorists.

In an interview with BBC Wales Today he said: "A quite unpleasant thread running through some of the national media and some of the interest groups pursuing an obsessional and irrational scheme to discredit the government's National Safety Camera project."

"They're not going to succeed."

A statement issued by North Wales Police on Thursday read: "The investigation and assessment of this matter has been conducted outside North Wales.

"We understand that the Crown Prosecution Service have concluded that there is insufficient evidence to prosecute Kate Brunstrom.

"The chief constable will not be making any personal statement about this matter, and as far as we are concerned the case is now closed.