Dublin councillor Liam Kelly is set to learn this week if he is to lose the Fianna Fáil whip on Dublin City Council following the publication in newspapers of photographs of him hunched over a white powder substance and holding a rolled piece of paper.
Mr Kelly has said that the mobile telephone photographs were staged by people in an effort to extort money from him.
He said he was not a drug user, and blood and urine tests could prove this.
A spokesman for Fianna Fáil confirmed yesterday that the party wrote to Mr Kelly late last week asking him to provide a written account of his version of events surrounding the taking of the photographs at a private party.
However, it is Mr Kelly's fellow Fianna Fáil city councillors who will decide whether he should be excluded from the party group on the council.
The 11 councillors plan to meet this week, and Mr Kelly should learn their decision by Thursday.
It is likely that any decision made by the group this week will not take effect until the completion of a Garda investigation into Mr Kelly's claims that the photographs were set up to extort money from him.
Mr Kelly has confirmed that he is the man pictured in the photographs which were published the weekend before last.
However, he has strongly denied using illegal drugs and he has reported the alleged extortion attempt to Santry Garda station in Dublin.
In a statement last week Mr Kelly said he had been "the subject of a very serious extortion attempt by the parties who have staged and taken the photographs. "This included a demand with menaces to me that a substantial sum of money be paid to the perpetrators. I quite rightly refused and reported the matter to gardaí.
"This extortion attempt is now the subject of a criminal investigation, something which refrains me from commenting on this matter any further in case that process becomes damaged."If he is removed from the Fianna Fáil group on the council, Mr Kelly would remain a member of the party until his membership is decided at national level. While the councillors have the power to remove the party whip from Mr Kelly, they have no power to remove him from the council.