TRAFFIC police were stunned when both a learner driver and the supervisor tested positive for cocaine.

However, officers were left frustrated when the pair had to be released without further action being taken, with medical professionals unable to take blood samples.

They were stopped on the A64 at Rillington last night by officers from the North Yorkshire Police's Roads Policing Group, who described the case as "unbelievable".

Police arrested the pair after using a device known as Drugwipe.

Sergeant Paul Cording, of North Yorkshire Police's Roads Policing Group, tweeted: "Sometimes this job really frustrates you. Sadly the medical professionals were unable to find veins on either of these people so blood could not be taken and legislation means we cannot revert to urine. So as it stands both were released no further action.

"We will however be contacting the DVLA for them to consider the status of their driving licences. Frustrating as it is, unfortunately the law states that for a section 5A drug driving offence only the sample has to be of blood."