A prison officer who was caught smuggling class A drugs into a top security jail has been sentenced to more than six years behind bars.

Heather McKenzie, 31, secretly ferried cocaine and mobile phones into HMP Shotts in North Lanarkshire.

The scheme was uncovered following a joint investigation by the Scottish Prison Service and Police Scotland amid suspicions about the growing number of drugs found in cells.

McKenzie, from Forth in South Lanarkshire, pleaded guilty at the High Court in Lanark last month to charges of supplying a prisoner and others with controlled drugs, phones and a Sim card.

She was jailed for six years and three months when she appeared at the High Court in Glasgow for sentencing on Thursday, the Crown Office said.

Prosecutors said that during the investigation, which began in March 2020, McKenzie was identified as a suspected drugs trafficker, and further intelligence suggested she had formed a close bond with a prisoner serving a life term.

The prisoner’s cell was searched twice and officers found quantities of cocaine and an iPhone, which on examination was found to contain calls and WhatsApp messages to McKenzie’s own mobile.

Data recovered from the phones revealed McKenzie discussed smuggling drugs into the prison on six separate occasions.

The court heard the prisoner arranged for unidentified individuals to meet with McKenzie to drop off drugs, phones and money.

Meetings were then arranged at various locations, including McKenzie’s home address.

Police officers who carried out a search of her home removed a haul which included £2,500 in cash, syringes, steroids, cocaine and benzocaine, which was recovered from a first aid box in a garden shed.

The court was told McKenzie, a first offender, appeared to have been paid money to smuggle the contraband into the prison.

McKenzie was suspended from the Scottish Prison Service during the investigation and dismissed following her conviction.

David Green, procurator fiscal for homicide and major crime, welcomed the sentence and said McKenzie, as a prison officer, had committed a severe breach of trust.

He said: “The public rightly must have confidence in prison officers to uphold the law. This individual abused her position and fell far short of the standards of professional conduct the public are entitled to expect from members of her profession.

“I hope this sentence sends a strong message to others involved in this kind of criminal behaviour and demonstrates that prosecutors will ensure that people who act otherwise than in accordance with their duties in public office will be brought to justice.”

McKenzie will now also be the subject of a Crown Office confiscation notice under proceeds of crime legislation.

A Scottish Prison Service spokesman said: “While the vast majority of our staff adhere to the highest standards of conduct, we are always vigilant to any potential corruption within our establishments.

“We have an increasing serious and organised crime population, and recently launched our first ever anti-corruption framework, which both supports staff who may be targeted and sets out a framework to assess, monitor, challenge and prevent illicit activity.

“As this case demonstrates, we will always work with Police Scotland to ensure any potential criminality is fully investigated.”