Philippine President Rodrigo Duterte has drawn criticism from rights groups after pardoning a US marine convicted of killing a transgender woman.

Mr Duterte issued on the pardon on Monday to Lance Corporal Joseph Scott Pemberton, who has been in prison since 2014 for the murder of Jennifer Laude.

Pemberton has served just over half of a 10-year sentence for the murder.

Virginia Suarez, a lawyer for Laude’s family, called the decision a “mockery” of the country’s justice system.

The pardon was announced by Mr Duterte’s spokesman, Harry Roque. “The president has erased the remaining punishment against Pemberton,” said. “He can now go home because of the pardon.”

The former US marine had been granted early release last week by a local court, for good behaviour, but the decision was being held pending an appeal by lawyers for Laude’s family. That process was negated by the pardon.

There was no immediate announcement of a release date.

Lawyer Virginia Suarez said in a statement: “This is another injustice, not only to Jennifer Laude and family but a grave injustice to the Philippine people. This is a travesty of Philippine sovereignty and democracy,” Ms Suarez said in a statement.

Pemberton met Laude in a bar in Olangapo in October 2014, while he was on leave after joint US-Philippines military exercises. Police said the pair checked into a hotel, where she was found dead the following day, slumped over the toilet, apparently strangled.

The marine testified in court that he had attacked Laude after he realised she was transgender, but claimed she was still alive when he left the room.

UP Babaylan, a local LGBT rights group, said in a statement co-signed by other rights groups that Mr Duterte’s decision sent a “loud and clear message that a Filipino trans woman’s life does not matter”.

The hastag #JusticeForJenniferLaude trended globally on Twitter on Monday. In one of the most shared tweets, Philippine human rights activist Chel Diokno called the pardon an “affront to Jennifer Laude and her family” and a “big step backward for justice in this case and in our country”.

Bahaghari, another Filippino LGBT rights group, tweeted: “For as long as the US maintains hegemony over our military, economy, and politics, there will be no #JusticeForJennifer and for the Filipino LGBTQ+.”

The murder case strained ties between the US and the Philippines, a former US colony where the Americans retain a significant military presence. Under the terms of a defence pact between the two countries, the US retained custody of the Pemberton throughout his trial and incarceration, meaning he served his sentence on a US military base rather than a Philippine prison.