MANILA (AFP) - A daughter of the late British baron Lord Moynihan has been killed in the Philippines where the government is waging a deadly war on drugs, police said Monday (Sept 19).

Maria Aurora Moynihan, 45, was shot by unknown attackers who left her by the side of a Manila street on Sept 10, authorities said.

Her killers left a cardboard sign accusing Moynihan of being a "drug pusher for celebrities", Chief Inspector Tito Jay Cuden told AFP.

The victim was on bail while facing charges of possession of illegal drugs following a February 2013 suburban Manila police raid.

"Witnesses told us they heard a series of gunshots, then saw a vehicle leaving the area. They did not see its licence plates," Cuden said.

CCTV footage aired on local television network ABS-CBN showed a vehicle stop and open its door on the deserted part of the street where the body was later found.

"She's considered a drug personality," Cuden said. No arrests have been made and an investigation is continuing, he added.

About 3,000 people have been killed since June 30 when Rodrigo Duterte began his presidency and proceeded to fulfil his campaign promise to kill 100,000 criminals and stop the country's slide to becoming a "narco-state".

A third of them died at the hands of police, while the rest were considered "deaths under investigation".

Cuden said the victim, who held dual British and Filipino nationality, is a daughter of the third Baron Moynihan of Leeds, who died in 1991 in Manila where he ran a string of brothels.

Anthony Patrick Andrew Cairnes Berkeley Moynihan fled to the Philippines in the late 1960s while facing a string of fraud allegations in Britain.

The British embassy in Manila told AFP it would issue a comment on the daughter's case later.

A sister, film actress Maritoni Fernandez, issued a brief statement on ABS-CBN last week expressing the family's "deep shock" over the killing and pleading for privacy to mourn the death.