A LAB technician has been jailed for three years after her boyfriend died of an overdose of drugs she had stolen from her workplace.

Katie Bradley, 26, twice stole bottles of the opiate-based Class A drug fentanyl from her employers, drug testing company Covance Laboratories, in Harrogate, and supplied it to her partner, Nathan Holmes, 31. The drug is 80 times more potent than morphine.

Prosecutor Nicholas Barker told York Crown Court yesterday Bradley had used cocaine, alcohol and fentanyl along with her partner on the evening of February 21 last year.

She fell unconscious and when she woke up found Nathan, who ran his own skip hire company, lying on the floor.

He had suffered a heart attack and was pronounced dead at Harrogate Hospital at 3.05am next morning.

Sentencing Bradley, the Recorder of York, Judge Paul Hoffman said: "What has happened here is a tragedy in which many people's lives have been shattered, but at least you have your life to get on with. He has lost his.

"On the first occasion you took fentanyl, you passed out and became scared of the effects. Despite this, you stole it again and supplied it again. The fact remains that you played a major part in events.

"Human life cannot be measured in terms of a prison sentence, but this must be a sentence to deter people from doing the same thing as you have done."

The court heard how Bradley, who lived with Nathan Holmes in Park Place, Knaresborough, was employed at the medical research company in Otley Road for six years.

She had been promoted in 2005 to support research into the effects of fentanyl on dogs, to find out whether it could be taken nasally by humans.

Bradley pleaded guilty to two charges of theft, two charges of supplying a controlled drug and one charge of possessing a Class A drug. She was sentenced to three years' imprisonment.

In mitigation, Alex Offer said Bradley had been badly emotionally affected by her boyfriend's death. He said that she had considered suicide and remained a state of shock and bereavement.

Speaking outside the courtroom, Nathan's father, Richard, said: "We feel lots of bitterness towards her. We feel she should have been up for manslaughter. She will be out in a year-and-a-half.

"We also feel a lot of bitterness towards Covance. The security must have been non-existent."

His mum, Charlotte, said: "Nothing is going to bring Nathan back but we would have liked a longer sentence. He was a harmless, lovely boy with lots of friends. He was there for everyone."