MANILA - A justice official on Thursday described as "revealing" deaths related to the country's anti-drug campaign, saying the initial review of "nanlaban" cases— or suspects killed after allegedly resisting arrest— "say a lot" about how police conduct their operations.

"From what we've seen so far, the cases are very revealing. They say a lot about what can be improved as far as police operations is concerned, the rules of engagement," Justice Undersecretary Adrian Sugay told ANC.

"I guess the value really is I hope it starts an investigation, a more in-depth investigation on the part of the PNP (Philippine National Police) as to how they conduct their operations," he added.

• Guevarra: Weapons in 'nanlaban' cases not examined but justice system working

Last year, the agency conducted an initial review of more than 300 cases related to the drug war, which were submitted to the Office of the President but have not been released to the public.

In February, Justice Secretary Menardo Guevarra revealed to the United Nations Human Rights Council for the first time that weapons used in “nanlaban” cases were not fully examined and law enforcement agents failed to follow standard protocol.

But various human rights groups said it was the Philippine government’s way of evading a full-blown independent international probe into the controversial drug war in the country.

• PNP opens drug war records of 61 cases to DOJ review - Guevarra
• PNP says willing to give DOJ access to entire drug war record

On Monday, Guevarra bared that the PNP would allow them access to 61 cases in relation to the anti-illegal drug campaign, saying the move was a "significant milestone."

PNP chief Gen. Guillermo Eleazar later said the police force was willing to give DOJ full access to its records.

In the interview, Sugay said they were hoping to finish the review by October. He said the Philippine Drug Enforcement Agency has also signified it was willing to open for examination some of its drug war cases.

"I guess this will be very important in setting the tone or finding initial issues with regard to these illegal drug operations," he said.

"Hopefully this will spur further investigation with regard not to just anti-illegal drug operations of the police but also our law enforcement agencies, but I guess also with regard to the general rules of engagement or protocols," he added.

After the review, Sugay said they would determine if criminal charges should be filed against law enforcers involved.

"This is really to ensure that those accountable are really brought to justice and that appropriate criminal and administrative complaints are brought against them," he said.

"Hopefully this allows the PNP an opportunity to look at itself, to review its rules of engagement and hopefully initiate reform," he added.

Police place the death toll in the drug war at over 7,000, but human rights groups believe there could be thousands more deaths. Authorities have said suspects slain in drug operations had violently resisted arrest, prompting police to defend themselves, but critics believe the state is behind cases of summary killings.