Foreign experts recruited to add legitimacy to Hong Kong's police watchdog quit Wednesday, saying the agency lacks teeth.

The expert panel's decision to stand aside is likely to increase pressure on the territory's government for an independent probe of police behavior during six months of pro-democracy protests.

Critics of the police watchdog had previously argued that the agency lacks independence and powers to credibly investigate policing of the protests.

A pro-democracy protester waves a flag as protesters and office workers stage a protests on a street at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. (AP PhotoMark Schiefelbein)

A pro-democracy protester waves a flag as protesters and office workers stage a protests on a street at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. (AP PhotoMark Schiefelbein)

The panel of international experts that the agency turned to in September for experience and advice ended up drawing a similar conclusion.

In a statement announcing their decision to quit, the experts from Britain, Canada, Australia and New Zealand said the watchdog suffers from “a crucial shortfall” in its “powers, capacity and independent investigative capability.”

Policing of the protests has led to a breakdown in public trust in the once highly respected 30,000-strong police force.

A pro-democracy protester waves a flag as protesters and office workers march past business shop lots during a protests at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. (AP PhotoMark Schiefelbein)

A pro-democracy protester waves a flag as protesters and office workers march past business shop lots during a protests at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. (AP PhotoMark Schiefelbein)

Since the protests started in June, officers have fired 26,000 tear-gas and rubber-baton rounds at demonstrators, arrested more than 6,000 people and faced broad condemnation for perceived abuses.

Pro-democracy protesters and office workers stage a lunch time protests at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. The placard in center carrying a photo of Hong Kong Chief Executive Carrie Lam reads "District Councils lost in election, means people don't want you in office. Five demands no one less". (AP PhotoMark Schiefelbein)

Pro-democracy protesters and office workers stage a lunch time protests at Causeway Bay in Hong Kong, Wednesday, Dec. 11, 2019. Hong Kong Chief Executive Carrie Lam on Tuesday again ruled out further concessions to protesters who marched peacefully in their hundreds of thousands this past weekend, days before she is to travel to Beijing for regularly scheduled meetings with Communist Party leaders. The placard in center carrying a photo of Hong Kong Chief Executive Carrie Lam reads "District Councils lost in election, means people don't want you in office. Five demands no one less". (AP PhotoMark Schiefelbein)