After serving a four-year jail sentence for drug-dealing, Niall Gallagher saw the error of his ways and obtained work helping other addicts.

But after being made redundant from his job as a community support worker, he returned to Class A drugs.

The 42-year-old addict fell for the charms of an undercover police officer and supplied her with heroin.

Now Gallagher, of Nelson Road, Gillingham, is back behind bars serving a three-year sentence.

He was arrested in a major operation code named Greengrass, aimed at infiltrating drug-dealing in Medway.

In total, 15 drug dealers arrested in Medway during a swoop by the Kent and Essex Serious Crime Directorate have this week been jailed for a total of 29 years and five months.

All were arrested in the Medway towns between February 29 and March 1 this year.

The crackdown was the climax of a three-month investigation by the Directorate involving undercover officers.

Throughout this week, all have appeared for sentencing at Maidstone Crown Court after previously pleading guilty to offences of supplying Class A drugs.

Several offenders have been sentenced at Maidstone Crown Court to either imprisonment or drug rehabilitation orders.

In Gallagher's case, he came into contact with undercover officer “Nicky” in Gillingham in October last year.

“They talked about drugs,” said prosecutor Denzil Pugh. “He had sorted himself out and said he could sort her out as well. She said she wanted heroin.”

Gallagher handed the officer a £10 wrap of heroin in Beaconsfield Avenue. Four days later, he again supplied her with a £10 wrap.

Philip Sinclair, defending, said Gallagher was a long-term addict. He was made redundant from his job as a voluntary worker and then suffered severe illness.

“He was placed on opium-derived painkillers,” said Mr Sinclair. “It caused his body to remember his addiction.

“He was approached by somebody who professed to be an addict. It is clear he took a shine to this young lady.”

Judge Michael Carroll said Gallagher had “exploited what he thought was her addiction to cosy up to her and be in her good books”.

He added: “In a way, this is slightly less pleasant than doing it for money. He is a mature man with a previous conviction for doing exactly the same.”

But Mr Sinclair suggested the officer exploited Gallagher’s vulnerability.

“He attempted to help her,” he said. “He was sympathetic because he found her attractive. Unfortunately, he is a weak man.”

Judge Carroll said if Gallagher, who admitted supplying drugs, committed such an offence again, he was looking at a seven-year sentence.

“The aggravating feature is you have done this before and you have not learnt your lesson.,” he told Gallagher. “You went into this with your eyes open.”