The state investigative body set up to probe allegations of Garda wrongdoing has branded the force's co-operation unacceptable.
The Garda Ombudsman said on one occasion it was forced to wait 542 days for a piece of information to be handed over during an inquiry.
In other cases, requests for information were refused or only controlled access to documents was granted.
Launching its annual report, the Ombudsman said that agreed protocols state the force must hand over documents to the watchdog within 30 days.
"We consider this situation unacceptable," the report states.