Criminals who should have been kept behind bars may have to be released while awaiting trial due to the coronavirus backlog, the head of the Metropolitan Police has warned.

Commissioner of the force Dame Cressida Dick told the London Assembly police and crime committee that, while magistrates' court are beginning to clear the delayed workload, it remains "very significant" in crown courts.

There is a particular "pinch point" for London because of the high number of complex, violent cases involving multiple defendants, the committee heard.

Dame Cressida said: "The challenge for London at the moment is within the crown courts.

"The backlog in crown courts remains very significant.

"London has a large number of cases which are quite complex with our levels of serious organised crime, they tend to be complex cases, multi-handed."

Police chiefs are in talks with the Government, courts service, judiciary and prosecutors about what can be done.

She said: "We will go for a remand in custody when we think they should be in custody, and then it's a matter for the courts how they decide to deal with that.

"Some of the custody time limits have been extended, what will happen next I honestly can't quite say.

"I am concerned that we by definition now have more risky people out on the street than we would otherwise have had."

Dame Cressida added: "We are coming close to the point perhaps where people who would have been kept in custody might have to be released.

"There is a particular pinch point for London and that is the number and volume of complex cases involving violent people which are very difficult to put to trial.

"We are not going to stop doing what we're doing.

"What we need to do as part of the justice system is make sure that crown courts can operate at maximum levels."

Trial dates are being set for late next year and into 2022, she said.

There is currently a backlog of around 50,000 court cases, exacerbated by the pandemic.

Justice Secretary Robert Buckland said earlier this month that 19 Nightingale courtrooms have been opened to help deal with the problem.