Police in Ireland have been coercing people to buy heroin in a bid to boost crime detection figures, according to a whistleblower.

Independent politician Luke "Ming" Flanagan said he has seen evidence provided to him by someone from inside the Irish police force Gardai that high-ranking officers have been involved in heroin dealing.

He told the Dáil, Ireland's parliament, that Garda (police officer) Nicky Keogh - based at Athlone Garda station – has handed the evidence over to retired judge Patrick McMahon, who is overseeing the allegations.

Flanagan said there are also allegations of a police cover-up and manufacturing of evidence. After helping with the allegations surrounding the police, Flanagan described Keogh as a "hero".

He added: "[The whistleblower's] greatest concern with the drugs operation in November 2009 is that there was a systematic and orchestrated effort by high-ranking Garda officers to induce and coerce Irish citizens - in this case with no previous criminal convictions - to buy drugs from drug dealers and in doing do, putting them in personal danger and in turn to sell drugs to undercover gardai without making any profit, thus boosting crime detection figures for arrest."

Flanagan, who represents Roscommon-South Leitrim, also said the whistleblower claims one of his fellow serving Gardai officers threatened one defendant to change his lea to guilty on the day of his trial.

"A further grave aspect, of grave concern, in relation to the planning of this operation was that the list of nominated persons to be targeted had a notable omission in that a significant and well-recognised drug dealer in the area who has been seen [to be] long associated with a senior member of the drugs unit was excluded," he added.

Flanagan said most of the people who had been targeted in the alleged operation now have serious drug offence convictions.

A Gardai spokesperson said: "The use by any member of An Garda Siochana of the confidential recipient mechanism is a confidential process and, as such, we are not in a position to comment on it at this stage."