A well-known Dublin solicitor has been linked by detectives to the money laundering operation which led to a former politician being questioned by the Garda last week.
The solicitor is believed to have handled funds channelled through a food company which is being investigated by the Criminal Assets Bureau.
Detectives are considering the roles of the solicitor and the former politician in the transactions, which are suspected of being a route to "legitimise" the proceeds of drug dealing by one of Dublin's major traffickers.
A file is to be sent to the Director of Public Prosecutions on the former politician, who made a statement to gardai after being questioned for 36 hours in Pearse Street station last week.
The bureau believes it has unravelled one of the methods by which the west Dublin dealer known as "The Penguin" laundered his money. The dealer is believed to be now in Amsterdam, although one of his closest associates was also questioned by bureau detectives last week.
The former politician could face charges as a result of the transactions being investigated. Senior bureau officers are examining whether he would be able to show that he had no suspicions about the origins of the money.
The extent of business dealings by the Penguin and other major traffickers is still unclear, partly due to the relatively lax regulation of companies in the Republic. One of the companies set up by the Penguin is jointly directed by him and Michael Boyle, whom he sent to London in 1995 to kill members of a crime family there.
The two men set up a trading and services company in 1993. The £2 company, with authorised share capital of £10 million, has official status as a legitimate commercial concern although it has not filed accounts or reports with the Companies Registration Office in Dublin since it was established.
In September 1995, Boyle's assassination mission to London was intercepted by British police. As Boyle opened fire on his victim, officers who had lain in wait opened fire on Boyle, hitting him five times.
The would-be assassin survived his serious injuries and was convicted of attempted murder at the Old Bailey last March. He received a life sentence.