British police on Thursday said they were investigating the criminal damage of a statue of former Ethiopian emperor Haile Selassie, which was smashed in a London park.

The Metropolitan Police said it received a report of damage to the statue in Cannizaro Park, in Wimbledon, southwest London, on Tuesday afternoon.

The damage appeared to have been carried out by a group of about 100 people, most of them men, according to one eyewitness quoted by the domestic Press Association news agency.

"I heard the statue being smashed up but didn't actually see it happen," said Andrew Morris, who was walking his dog in the park at the time.

"They (the group) weren't some rabid mob. They looked pretty calm. I didn't think they were in danger of attacking anyone."

The damage to the statue comes after two days of deadly protests in Ethiopia following the murder of a popular singer from the country's largest ethnic group, the Oromo.

Hachalu Hundessa, whose political songs gave voice to grievances of the Oromo people, was shot and killed on Monday night, sparking angry protests that by Wednesday left 81 dead.

Morris said the group in Wimbledon had fliers with Oromo slogans. Police said no arrests had been made.

Haile Selassie, Ethiopia's last emperor, lived in exile in Wimbledon in 1936 after his country was invaded by Italian forces.

The statue in Cannizaro Park - a head and shoulders bust in stone - was made by his former host, the sculptor Hilda Seligman.

It originally stood in the grounds of Lincoln House, on the edge of Wimbledon Common where Selassie took refuge, but was later moved to the nearby park. 

It was restored in 2005 after falling into disrepair, according to the Wimbledon Society heritage group.