Prosecutions may run in parallel with the Morris tribunal which is investigating incidents in Donegal, writes Carol Coulter, Legal Affairs Correspondent.
Allegations against members of the Garda Síochána in the Donegal division had been circulating for some time, but seemed to be getting nowhere until the setting up of the Morris tribunal.
True, two members of the force had been arrested and charged, along with an unemployed man, Mr Bernard Conlon from Sligo.
One of the gardaí charged, Garda John Nicholson, pleaded guilty to issuing fraudulent claims for court witness expenses to Mr Conlon and received the benefit of the Probation Act.
The other garda, Sgt John White, refused to answer any questions about these payments, but was charged in relation to a separate offence, the possession of a firearm at a Travellers' camp in Burnfoot, Co Donegal.
However, no charges arose from the serious allegations made by members of the McBrearty family. These included that they had been falsely accused of the murder of cattle-dealer Richie Barron, that a false statement had been concocted by gardaí implicating Mr Frank McBrearty jnr in the murder and that they had been subjected to a campaign of harassment emanating from the gardaí.
Sgt White featured in a number of these allegations.
Nor were there any charges relating to allegations involving other people, including that members of the force had planted explosives devices in order to enhance their reputations and that other gardaí had planted evidence on Travellers suspected of involvement in the murder of a Co Mayo shopkeeper Mr Fitzmaurice, and that they had also planted explosives on a telecommunications mast which was the subject of protests.
The latter allegations also concern Sgt White, though the Morris tribunal has stressed that the outlining of such allegations does not make them true. The alleged finding of a firearm at the Travellers' camp was dealt with at length by Mr Peter Charleton SC, in his opening statement to the Morris tribunal late last year.
None of the Travellers was ever charged in connection with this incident and, indeed, the only person charged in connection with it has been Sgt White.
But Mr Charleton pointed out that a number of other gardaí, including a local representative of the Garda Representative Association, had made statements about the search of the camp at the time which could amount to "manufacturing a defence" for Sgt White.
Most of the allegations under investigation at the Morris tribunal were the subject of an inquiry carried out by the Assistant Commissioner, Mr Kevin Carty.
This led to a report which was given to the Director of Public Prosecutions, who brought the prosecutions against Sgt White, Garda Nicholson and Mr Conlon.
However, the Carty inquiry has continued and it was his team which arrested the three gardaí at the weekend.
New information has come to light, both through the Morris tribunal and through separate developments, such as the finding of a miscarriage of justice in favour of Mr Frank Shortt by the Court of Criminal Appeal.
That court found that the accounts of two other gardaí, who had investigated allegations against Mr Shortt of permitting the sale of drugs, were not credible.
This case also brought to light the relationship between two of these gardaí, Sgt Noel McMahon and Supt Kevin Lennon and a purported informer, Ms Adrienne McGlinchey.
The revelations made during the Shortt appeal may provide the basis for further arrests. The use of informers is another topic being examined by the Morris tribunal.
However, this is a more sensitive one for the gardaí and the Garda Commissioner, Mr Pat Byrne, is claiming privilege for certain documents sought by the tribunal relating to this area of Garda operations.