Philippine authorities will investigate the possible link between drug syndicates and human rights groups, which have been critical of President Rodrigo Duterte's war on drugs, officials said on Tuesday.

This was after statements made by Foreign Affairs Secretary Alan Peter Cayetano and Presidential Spokesperson Harry Roque that drug syndicates could have been using the human rights groups to discredit the government's campaign against narcotics.

"We still have to dig further on this. But you can see the attack against the anti-drug campaign, while law enforcement agencies like PDEA (Philippine Drug Enforcement Agency) and the PNP (Philippine National Police) are making honest efforts on the ground," said PDEA spokesperson Director Derrick Arnold Carreon in a press briefing in Malacanang.

He expressed belief the attack by the human rights groups were on the campaign itself and "not just about the deaths arising from such operations."

He said PDEA would closely coordinate with its counterparts from the Philippine National Police, the National Bureau of Investigation and other concerned intelligence agencies in the investigation, to include some personalities from the human rights groups.

He said because of criticisms by human rights groups, their campaign has been doubted.

Philippine National Police spokesman Chief Superintendent John Bulalacao admitted that they did not have any concrete information to back up the claim of the two Cabinet officials at the moment.

But like PDEA, he said they would continue to validate such report that the drug syndicates could have been using the human rights groups to discredit the government's efforts against illegal drugs.

Since July 1, 2016 up to March 20, 2018, Carreon said there were 4,075 drug personalities who died during the anti-drug operations.

The Duterte administration has been criticized locally and internationally due to the high number of individuals who have been killed in the intensified campaign against narcotics.

Carreon also noted that a total of 469 government workers were arrested nationwide for violation of Republic Act 9165 or the Comprehensive Dangerous Drugs Act of 2002 since the war on drugs was launched by the administration. Out of the figures, 199 were elected officials, 45 were uniformed personnel and 225 were government employees. Celerina Monte/DMS