Mistakes have continued to be made by some Garda members classifying homicides despite revelations about such errors last year and assurances the problems were being addressed.
The head of the Policing Authority, Josephine Feehily, said there were concerns some of the cases had not been fully investigated.
A public meeting between the authority members and Garda Commissioner Drew Harris and his team heard in some cases more than one file existed for the same person on the Garda's Pulse database.
This had created difficulties when recording their deaths and classifying them.
And in other cases murders, manslaughters and other forms of unlawful killing such as death caused by dangerous driving were still being classified as the wrong crime.
"We're concerned that having spent a lot of time on this, it was important that it didn't become continuous," Ms Feehily said.
The authority’s overarching concern was that each killing that required a homicide inquiry received one; as is stipulated in the European Convention on Human Rights.
“If the data isn’t right, then there is a risk the investigation is not comprehensive,” she said, adding there were also some unanswered questions about investigations.
While the results of a major internal review into homicide cases is not yet complete, the Policing Authority has received some findings from senior Garda officers.
Between 2013 and 2015, for example, there were 98 charges of murder in the State. But when those cases were checked recently the classifications for 13 needed to be changed.
Of the remainder, the classification for 78 cases was accurate and seven cases were still before the courts; including for trial, sentencing or appeals.
Dangerous driving
And of 122 cases of dangerous driving causing death, some nine classifications needed to be changed, 97 were accurate and 16 were still before the courts.
And when 167 homicide cases were checked on Pulse and also checked on the records of the Office of the State Pathologist, there were unspecified shortcomings with four investigations and 14 other killings required follow-up queries.
The authority is set to receive further updates as a review of homicide cases continues within the Garda.
The Irish Times revealed last February that two civilian data analysts within the Garda had clashed with senior officers about how homicides were being classified and counted.
In some cases, when women were killed in their homes by their partners, the cases had mistakenly been classified as non-fatal assaults, for example.
And the civilian analysts also complained they had been refused access to investigation files by their sworn Garda colleagues.
It meant they could not determine if the appropriate criminal investigation had been carried out into those unlawful killings that had been classified incorrectly.
The civilian analysts clashed with Garda officers for over a year before making a disclosure to the Oireachtas Committee on Justice in February.
Since then a major review into how killings were classified and investigated by the Garda over the past 15 years was commenced and is continuing.
Garda Headquarters has repeatedly insisted that all killings were properly investigated and any errors made only related to how the cases were classified on Pulse.
But the authority said it wants proof before it could accept those assurances.
