The Australian federal police used a database that is known by law enforcement agencies to be “non-definitive” to brief the prime minister Tony Abbott on whether Man Haron Monis had a New South Wales firearm licence.

On Thursday the AFP confirmed it was the agency that provided the information to the prime minister, and that there was no record of Monis “ever having held a firearm licence” in NSW.



On Wednesday evening the prime minister’s office was forced to issue a clarification after Abbott incorrectly told reporters that Monis, who took 17 people hostage in the Lindt cafe in Martin Place on Monday, held a NSW firearms licence.



The prime minister’s statement said the AFP was investigating how the National Police Reference System (NPRS), which is a central database for sharing information between state and federal law enforcement agencies, had given the wrong information.

The AFP said the information was “based on a manual entry” in the NPRS, and it was working with Crimtrac, which manages the database, and “federal and state partners” to “establish the source of the entry, and to identify any shortfalls within the current system”.



An agreement between Crimtrac and the state and federal police makes clear that the database should not be used as a definitive reference point for information, according to documents released under freedom of information laws.

“Under this agreement it is acknowledged by all parties that information contained in the NPRS system cannot be considered to be definitive in nature,” the 2009 agreement said. “That is, data contained in PAPJ [participating Australian police jurisdictions] operational systems is accepted as the authoritative source pertaining to any person of interest and supersedes any data contained in NPRS.”



The agreement continues: “NPRS remains a reference tool whose data is sourced from PAPJ systems but is not linked in a manner to reflect exactly PAPJ operational systems.”



There have been large omissions from the database in the past. A 2013 auditor general’s report in WA found more than 25,000 instances in which the West Australian police firearms management system and the national database could not be reconciled because of “data incompatibilities”.



The AFP statement also said the database was a “consolidation of person of interest information provided by all police agencies which is managed by Crimtrac on their behalf”.



The authoritative source of data remains with the originating agency. It is unclear at this point whether the national security officials who briefed Abbott on the gun licence had checked with the NSW police firearms registry. Online searches can be conducted by any member of the public in NSW to determine whether a gun licence is valid.



Several Sydney firearms dealers told Guardian Australia they used the NSW registry to check a firearms licence if they were concerned about its validity. They do not check interstate licences.



Guardian Australia has also obtained documents under freedom of information laws that show a review may be considered into the way Crimtrac shares data between state and federal agencies.



Minutes from a September 2013 Crimtrac committee meeting states that the agency has been considering operating a model adopted by the United States to improve its handling of information with a system known as the “national information exchange model”.



A broad review has been commissioned by the government into the circumstances of Monis’s access to firearms, his release on bail and events leading up to the hostage crisis.