A KEIGHLEY man died of drug and alcohol poisoning on the same day he became involved in an undercover police operation to stamp out drug-dealing in the town, an inquest heard.

James Varey, 38, died at his Marley Street home on June 13, 2012, after he was said to have taken heroin bought in the company of two plain-clothes officers.

A jury heard the officers had been working on a covert aspect of Operation Lambfield, set up at the end of May 2012 to reduce crime in Keighley, including drugs offences.

Assistant Bradford Coroner Neil Cameron told the inquest, held at Bradford Crown Court, the two officers were with Mr Varey when he bought heroin from a local dealer and he left with it in his possession.

Detective Superintendent Stephen Bennett, the officer who authorised the covert tactics, said Mr Varey was not known to the officers who only researched him after the deal was made - and discovered he had died later the same day.

"When they returned to their station and did their research on him, they found out he was deceased," he said.

"Only then did they find out he had drug and alcohol problems."

Ifeanyi Odogu, acting on behalf of Mr Varey's family, said there was no operational order for Operation Lambfield highlighting the potential risks to members of the public who might come into contact with officers.

Addressing DS Bennett, he said: "This was not a suitable operation for you to authorise."

In response, DS Bennett, who admitted using drug abusers to get to dealers had been a tactic of the operation, said all the required details had been included in the authority document he signed off.

"The operation was to understand the network of drug dealing in Keighley, if we had arrested someone on day one, there would have been no point," he said.

When asked if officers were trained to judge people at risk, DS Bennett said: "Yes, if they feel there is a vulnerability about that person, they should know how to react.

"There are processes and policies to deal with threats to life, and I was satisfied they were in place if officers met with a vulnerable person."

A toxicology report into Mr Varney's death, read out in court by Dr Richard Shepherd, the consultant forensic pathologist who carried out the post-mortem examination, said the combination of a high level of alcohol, along with morphine and methadone, "could well account" for his death.

Dr Shepherd confirmed the cause of death as alcohol and mixed drug poisoning.

A sample of his blood was found to contain 314mg of alcohol per 100ml of blood, nearly four times the legal drink drive limit.

The sample also contained 0.24mg of methadone - a drug prescribed as a substitute for heroin - and levels of morphine and codeine, described as indicators of the use of street-based heroin.

The inquest continues.