LONDON - A member of the British parliament on Sunday vowed to scrutinize his country's export of surveillance equipment to Manila, saying this may make UK "complicit" in the alleged extra-judicial killings under the Philippines' war on drugs.

The UK government sold £150 million or nearly P11 billion worth of advanced spying equipment to the Philippines in July 2016. The deal included IMSI catchers that are used to eavesdrop on telephone conversations, as wells as surveillance tools for monitoring internet activity.

President Rodrigo Duterte is facing an investigation before the International Criminal Court (ICC) for alleged crimes against humanity under his war on drugs, said British Member of Parliament Lloyd Russell-Moyle.

"The Philippines was one of the countries in the report in 2016 listed where we would monitor closely and limit weapon sales, and we haven't seem to have done, and if those sales are aiding and abetting the crimes that the President is committing, we are then are complicit in the process," he said.

Russell-Moyle, who is also a member of the UK Parliament’s committees on arms export control, said he will raise the issue before the chamber.

"I will raise them at the leader at the House and we will continue to try and scrutinize further sales that might be in breach of the consolidated criteria," he said.

Under the law, the UK government may not allow an export of products if there is a clear risk that these might be used for internal repression, Russell-Moyle pointed out.

"Knowing exactly where its being used is a very difficult task. That is why we have a criteria that we should presume against selling if is the country is engaged in the repressive acts, and a referral to the ICC is an indication that the government is engaged not in legitimate war on drugs but in illegitimate war on drugs that is executed in a brutal way," he said.

"A number of arms and export licenses have been withdrawn from the Philippines so we might see that increasing" he added.

Human rights groups have claimed that some 12,000 drug suspects have died since President Rodrigo Duterte launched his war on drugs in 2016. Data from the PNP places the death toll at some 4,000.

Officials have maintained that suspects killed in police operations fought back.

• Nanlaban lahat? Cayetano defends drug war deaths

Chatham House scholar Dr. Champa Patel said the international community should continue monitoring the campaign.

"We need to understand that it is an ongoing situation, it needs careful monitoring. It's not something that because the ICC opened an investigation, it's in the past. It's critical that the people keep an eye on the situation," he said.

UK, which has business interests in the Philippines, should speak out about the issue, Patel said.

"The UK wants to position itself as country that promotes law and order and in that respect, it is incumbent on them to speak when they see clearly a violation of human rights," he said.

The ICC recently started its initial review into a communication filed by a Filipino lawyer alleging crimes against humanity in Duterte’s drug war.

Duterte last week said the ICC cannot have jurisdiction over him, as he again defended his war on drugs.

• Duterte tells ICC: You can’t have jurisdiction over me

Russell-Moyle said he has yet to confirm if there is a pending arms deal between the Philippines and the UK.

The Philippine Embassy in the UK, meanwhile, declined to comment on the issue for now.