A 54-year-old motorist who drove under the influence of benzoylecgonine, a metabolite of cocaine, has been fined £1,250 and banned for two years.

Lisa Maria Harrison was stopped by police on September 7 and was later found to be nearly five times the legal limit for the drug.

Magistrates also ordered her to pay £125 prosecution costs and to take an extended driving test at the end of her ban.

Prosecuting advocate Harry Bellis told the court that police stopped Harrison while she was driving a Renault Megane, on September 7, at 6.16pm, after information was received that she may be under the influence.

A drug wipe test proved positive for cocaine and she was subsequently arrested.

A blood sample was taken at police headquarters, which later produced a result of 240 for benzoylecgonine, which has a legal limit of 50.

Defence advocate Ian Kermode said that Harrison admitted that she had taken cocaine several days prior to driving.

Mr Kermode said that she had initially pleaded not guilty, while a report was obtained looking into whether other prescription drugs could have affected the reading.

Once this was ruled out, he said that his client had changed her plea to guilty.

Mr Kermode referred to a probation report which said that the defendant had believed the substance would be out of her system by the time she drove.

The report assessed Harrison, of Newtown Estate, Santon, as a low risk of reoffending.

Mr Kermode said that the defendant was on benefits, having been unemployed for five years, but had caring obligations.

Magistrates Chair David Christian told Harrison: ‘To be five times the legal limit is very alarming.’

Harrison agreed to pay the fine and costs at a rate of £10 per week.