A SINGLE Dorset police officer is responsible for more than a third of all drug-drive arrests in the county.

PC Dave Cotterill, a traffic officer based at Poole, made 238 drug-drive arrests in the last year - 37 per cent of the total.

Legislation introduced in 2015 set levels for 17 different drugs. Police can now pull vehicles over and conduct a roadside test for drivers suspected of having taken drugs.

PC Cotterill, who has served with the traffic unit for around four years, said he has arrested people aged between 17 and 65 for the offence.

Last week, he arrested a suspected drug driver who had passed his driving test the day before.

"The manner of driving gives it away sometimes," PC Cotterill said.

"They might not be driving in a straight line, for example. I do the drugs wipe only when I'm suspicious that they're under the influence.

"You need to have a suspicion about them to do it."

Drivers arrested for being under the influence are often initially pulled over for different reasons, including using their mobile phone at the wheel or driving without a seatbelt.

If an officer then suspects they may have taken drugs, a test will be carried out. If the test is positive - a process which can take up to two minutes - the driver is arrested and taken to the police station for a further blood test.

Those convicted of drug driving face a ban of at least 12 months.

In 2017, there were a total of 678 drug-drive arrests. Officers from a range of different units are trained to carry out drugs wipe tests.

PC Cotterill said he becomes suspicious when someone has taken drugs if they are excessively nervous when pulled over.

"They might be pale, or sweating," he said.

"Sometimes you can tell from people's eyes - if their pupils are dilated, it could be that."

In August 2017, Alanda Pike caused the death of her three-year-old daughter Louisa when three times the limit for alcohol and cocaine derivatives.

Pike, 34, had been drinking and taking the class A drug with her partner the night before the crash, which took place at Thickthorn Cross on the A354 Salisbury Road, near Blandford.

She was jailed for six years and four months.

Sid and Barbara Samways, 74 and 71, died in April last year after their Kawasaki motorcycle was involved in a collision with Jamie Myers' Ford Escort on the Higher Shaftesbury Road in Compton Abbas.

Myers had 211 micrograms of benzoylecgonine, a metabolite of cocaine, per litre of blood some seven-and-a-half hours after the crash.

The limit is 50ug/l. Myers was sentenced to five years in prison.

PC Cotterill said: "Drug-driving kills.

"We have seen cases like that in Dorset. People have taken drugs and caused terrible crashes."