Investigators examining the activities of the Maple Ten group of investors in the purchase of Anglo Irish Bank shares are now satisfied that all of them will co-operate with their inquiries.
The Office of the Director of Corporate Enforcement (ODCE) used new legislation, introduced last month, to bring one Naas-based investor, Gerry Conlan, to court on Monday to ensure he would co-operate.
Naas District Court ordered Mr Conlan to make himself available as a witness in the investigation. Lawyers for the property developer said he would be complying with the order.
The legal move was made by a garda detective inspector, seconded to the ODCE, which is investigating the loans deal Anglo provided to some of its top clients to buy up shares owned by Sean Quinn in a desperate bid to stop the bank collapsing.
It was the first time that the powers contained in the new legislation were used.
Investigators said last night that the rest of the Maple Ten had co-operated with their investigation and had answered questions about the purchase of the bank shares.
Inquiries are being carried out to determine if the shares transactions breached company law.
However, a number of high-profile players in Anglo are expected to be re-interviewed by detectives from the Garda Fraud Bureau as part of their investigation into suspected financial irregularities including a "back-to-back" deposit arrangement undertaken between Anglo and Irish Life and Permanent for the benefit of Anglo at the end of its financial year in 2008.
This allowed the money to be moved back and forth between the two institutions, boosting the appearance of Anglo's financial health.
Those facing re-interview could include former Anglo chairman Sean FitzPatrick, and the bank's ex-financial director Willie McAteer, who were arrested previously for questioning.
Gardai are expected to submit a file within a month to the Director of Public Prosecutions, who will determine if criminal charges should be brought against any suspect.
Earlier this month, the Irish Independent disclosed that a decision had been made to complete the file without interviewing the former Anglo chief executive, David Drumm, who is living in the US and has ignored repeated requests by the gardai to co-operate with their inquiries into the suspected offences.
Mr Drumm cannot be extradited back to Ireland from the US for questioning about an alleged crime.
A warrant can only be issued if a criminal charge has been brought against a suspect and the court is satisfied that the evidence is sufficient to justify a prosecution.