A speed camera in Cardiff could be the UK's most prolific after generating more than an estimated £800,000 worth of fines in just six months.

According to road safety group GoSafe Wales the device on the junction the city's Newport Road and Colchester Avenue caught 13,624 speeding motorists and a further 146 running red lights between January and June.

Last year, a Freedom of Information request revealed the highest grossing camera in the UK was one the M60 near Stockport, which caught more than 32,000 motorists in three years.

However, its Cardiff cousin could eclipse that figure. If it continues at its present rate, by 2017 it would have caught more than 82,000.

Tim Shallcross, from the Institute of Advanced Motorists (IAM), said the whole purpose of speed cameras was to slow cars down.

He said: "If a camera is issuing a small number of fines, or none at all, it's doing its job. But if this camera in Cardiff is ticketing that many people, it's not having that effect. More than 13,000 is abnormally high number of offences within a six month period.

"The local authority, which is responsible for road safety, should be looking at those figures and saying, 'We seem to have an issue here - the camera is catching a lot of people. Let's make sure that it looks like a 30mph highway, and that the cameras are clearly visible and the signs aren't obscured by vegetation'. That's the approach they should be taking."

GoSafe Wales figures show that of the 13,624 served with a notice of intended prosecution by the Cardiff camera, almost 6,000 took up the offer of a speed awareness course while more than 3,000 ended up paying a speeding fine instead.

Based on the typical £85 cost per place on speed awareness course and a minimum speeding fine of £100, the camera would have netted around £808,410.

The camera's figures for this year are markedly different to those from 2013 - when just 318 tickets were issued.

The GoSafe partnership - which operates road safety cameras in Wales - said the device had not come into full operation until 2014.

It also said the road was one of the main routes into Cardiff - "hence the figures".

Partnership manager Chris Hume insisted excessive and inappropriate speed remained a major factor in road deaths.

He said: "The A4161 receives on average 1,600 vehicles travelling through Newport Rd via Colchester Avenue, Cardiff per day.

"Motorists should comply with the relevant speed limit which is there for a reason.

"Our main priority is to continue to educate motorists about the effect of inappropriate speed, with enforcement being the last resort after engineering solutions are considered.

"The revenue from speeding fines is returned back to the Government and not the partnership.

"There is a simple message - cameras are in place to save lives not to make money."