The Planning and Payments Tribunal has finished direct evidence following ten years of testimony.
Chairman Judge Alan Mahon has previously said the final cost of the inquiry could reach €300m.
Judge Mahon said the tribunal begun public hearings in1998 after the inquiry was set up the previous year.
It has sat for a total of 916 days. In the past six years it has generated 60,000 pages of evidence and 76,000 pages of correspondence with 400 witnesses.
The chairman paid tribute to the tribunal team. He said although it was a daunting, stressful and inconvenient experience for many of the witnesses, the tribunal had only rarely had to use its power of subpoena to compel them to attend.
The three judges of the tribunal are now expected to take up to a year in drawing up their report.
They will decide on the credibility of former lobbyist Frank Dunlop and former developer Tom Gilmartin, who gave both evidence of corruption in Dublin's planning process.
After the report they will have to decide on legal costs for witnesses which Judge Mahon has previously admitted could bring the total cost of the tribunal to €300m.
The inquiry has already cost more than €70m for the tribunal's own legal and administration costs.
The only piece of testimony left is a short cross-examination by former council official George Redmond of a witness from the Carrickmines module.
But Jidge Mahon said today effectively marked the end of the tribunal's sittings.
