The garda watchdog expects its investigation into the Corrib rape tape controversy to be completed within weeks.
Dermot Gallagher, chairman of the Garda Ombudsman, said all gardai at the centre of the inquiry have been interviewed.
The video tape - in which officers were apparently inadvertently recorded joking about raping a protester at the controversial Shell pipeline in north Mayo - has been sent outside the country for forensic analysis.
"There's some more evidence to be gathered," Mr Gallagher added. He believes his investigators should have their report into the incident finished before the end of the summer.
It's understood the tape was sent to the Police Service of Northern Ireland for technical tests to confirm its authenticity.
The Garda Ombudsman said it had considered a number of years ago probing the wider problem of relations between the force and protesters at the gas project, but the idea was shot down as inappropriate at the time, and complaints are now significantly lower than in the earlier days of the demonstrations.
The garda has already carried out its own internal fact-finding mission into the affair and is awaiting the ombudsman's report.
Launching its annual report, the ombudsman revealed it received 2,258 complaints from the public and 103 referrals from Garda Commissioner Martin Callinan last year.
In all there were 4,931 allegations of garda misconduct, but just over 1,000 of these were deemed inadmissible.
In its first full profile of complainants, the ombudsman revealed people coming forward with grievances are most likely to be university or third-level college educated homeowners, white, Irish and in good health.