Minister for Justice Charlie Flanagan has signalled he would consider launching an inquiry into claims that gardaí colluded with a criminal gang in the sale and supply of heroin in the Midlands in certain circumstances, according to documents seen by RTÉ.

RTÉ's This Week programme has learned that Minister Flanagan wrote to the solicitor representing a garda earlier this month, in which he said that in the event that current long-running probes into the claims proved "inconclusive", he would examine the establishment of an inquiry to look into "the substance of the allegations".

It has been claimed that a well-placed garda used his influence to assist the drug gang, which was based out of Athlone but supplying heroin all across Westmeath, Offaly and Laois - which are coincidentally in the heart of the Minister's constituency area.

The Minister's letter was written on 6 December, to John Gerard Cullen, solicitor for Garda Nicky Keogh, who was named in the Dáil as having raised concerns with senior garda management about the alleged garda collusion with a drugs gang.

Mr Keogh first made his concerns known to garda senior management in 2014. 

In the letter seen by RTÉ, Minister Flanagan said he "appreciates that Garda Keogh is frustrated by the lapse of time since he came forward with his allegations".

Garda Keogh also alleged that after raising his concerns he was subject to maltreatment within the force, and he is expected to be providing a statement to the upcoming Disclosures Tribunal on the matter.

Mr Cullen had written to the Minister in November, seeking an update into the current investigations, as well as other documents relating to the case, including a special report ordered at the behest of his predecessor, former tánaiste Frances Fitzgerald last year.

In his reply on 6 December, Mr Flanagan said these reports and documents could not be provided to Garda Keogh, nor could the Minister's office involve itself in the independent investigations of An Garda Síochána into an alleged act of criminality.

However, the Minister said that he was seeking an up-to-date report on the matter from the current acting Garda Commissioner Donal Ó Cualain, as well as giving the undertaking that "should the investigations prove inconclusive when finalised, the establishment of an inquiry would be examined to address the substance of the allegations".

Speaking in the Dáil in October 2016, in heated exchanges between herself and Independents4Change TD Mick Wallace, the then Justice Minister Frances Fitzgerald said she was deeply concerned with matters relating to policing in Athlone which had been raised with her, and also committed to inquiring into the case, should matters not be addressed.

However, Mr Cullen said that Minister Flanagan's commitment to act only if the current investigations proved inconclusive was "inadequate".

"Many a miscarriage of justice proved very conclusive," he said, and described the Minister's commitment as "vague" and "non-specific and meaningless".

The Department of Justice did not respond to a series of questions on the matter while the garda press office said it did not comment on correspondence between third parties.