The Philippines President Rodrigo Duterte's bloody drug war has been one of the most controversial human rights issues globally in the past several months. But, how many drug offenders and drug pushers have been killed in the campaign?

An opposition lawmaker critical Duterte's administration says that 20,000 people have lost their lives during the entire offensive. Still, it is not clear whether it includes extrajudicial killings by vigilante groups and hit squads.

Addressing the Philippines Senate on Wednesday, 21 February, opposition lawmaker Antonio Trillanes said the government's own reports show there have been at least 20,322 drug-related killings.

"While the country continues to laugh at the lewd jokes of Duterte, more than 20,000 of our countrymen have been killed," said Trillanes speaking in a mix of Filipino and English. "They basically admitted that there are no so-called vigilante killings – that these deaths are actually state-sponsored executions."

The former military officer added that Duterte "flaunts as an accomplishment the killing of people he despises". He cited the official document entitled "Fighting Illegal Drugs: Real Numbers" in which the killings are being described as accomplishments.

But, Trillanes's remarks have been opposed by Duterte's supporters, saying the operations were carried out in line with police protocols and allegations of extrajudicial killings are being probed already.

The International Criminal Court (ICC) has recently said it is set to open a preliminary inquiry into the alleged human rights crimes taking place under Duterte as there have rampant reports of extrajudicial murders targeting drug users.

"Specifically it has been alleged that since July 2016 thousands of persons have been killed for reasons related to their alleged involvement in illegal drug use or dealing," said chief prosecutor Fatou Bensouda.

"While some of such killings have reportedly occurred in the context of clashes between and within gangs it is alleged that many of the reported incidents involved extrajudicial killings in the course of police anti-drug operations," she added. However, the Duterte administration derided the move saying the international body is wasting its resources on a non-existent matter.

More than one right group have alleged that the Duterte government has been carrying out serious human rights violations under the banner of the anti-narcotics campaign.

"We need to get to the bottom of this, how many people were exactly killed, who are the perpetrators? It is about time that we have a proper accounting of the deaths," Carlos Conde, a Human Rights Watch representative in the Philippines, told the Al Jazeera.

Duterte came to power in May 2016, riding on the wave of a harsh anti-drug rhetoric. He sought three to six months to wipe out the illicit drug trade, which has been crippling the Philippines, but he has then repeatedly extended the bloody campaign until all the drug addicts and drug pushers are wiped out. The violent battle against illegal drugs has earned him global notoriety since he took over the office.

Duterte State of the Nation address
Philippines President Rodrigo Duterte gestures as he delivers his State of the Nation address Noel Celis/AFP