An officer of the Director of Public Prosecutions has told the trial of a detective charged with forging a DPP letter that there was no file for a priest the detective was investigating for child abuse.

Wicklow detective Garda Catherine McGowan (aged 48), who is based at Bray Garda Station, has pleaded not guilty to one count of forgery on January 15, 2009 at Bray Garda Station and two counts of using a false instrument at Bray Garda Station and at Harcourt Street Garda Station between June 21 and 22, 2011.

The instrument is alleged to have been a letter from the office of the Director of Public Prosecutions (DPP), dated January 14, 2009.

On day three of the trial, Henry Matthews, a professional officer in the DPP's office, told the jury at Dublin Circuit Criminal Court that his job was to assess garda investigation files and make decisions on whether or not to prosecute the cases.

He told Alex Owens SC, prosecuting, that in 2011 he was asked to check his office filing systems for a file for a priest who Gda McGowan was investigating from 2007 after a Wicklow woman made an allegation of sexual assault against him.

The 2011 investigation of Gda McGowan’s handling of this allegation was prompted by the publication of the Murphy Report which investigated clerical sexual abuse in the Dublin area.

The priest was one of the clerics mentioned in the report.

Mr Matthews said that in July 2011 he was unable to find a case file for a suspect with the same name as the priest for a charge of sexual offence.

Caroline Halstead told the trial that she worked as a legal secretary to James Boyle, the state solicitor for Bray and Kildare at the time.

Ms Halstead said she was involved in the processing of files which involved manually logging hard copies of new files as well as recording them on to a computer filing system.

She said that her office did not have any records between 2005 and 2009 of a file for the priest that Gda McGowan was investigating. She testified that she checked both the manual and computerised filing systems.

The complainant in the clerical abuse allegation has testified that in late 2009 Gda McGowan told her she had sent a file to the DPP and the DPP had directed no prosecution.

Sergeant Diane Swift previously testified that during her review of the case Gda McGowan provided her with statements relating to the abuse case and a photocopy of a letter purporting to be from the office of the DPP.

The witness said the letter read: “Dear Sir, I (illegible) to yours. In (illegible) the statement of the complainant…could not possibly form the basis of a prosecution given that the complainant’s allegation of rape is only conjecture.”

The letter was signed by a person with the title of “professional officer”.

The trial, which is scheduled to last two weeks, continues before Judge Mary Ellen Ring and a jury of six men and six women.