When they come to court, there are a lot of frivolous adjournments

Les Thorne London magistrate

But some magistrates are worried the figures do not take into account what they say is a growing number of cases that collapse.

They argue some defence lawyers are using legal loopholes to make sure cases keep getting postponed.

Cutting reoffending

Such delays can mean witnesses fail to appear at later court hearings.

The fall in the amount of time between arrest and sentencing does cut the chances of young offenders committing more crime while they wait.

The latest figures are for February, when the average time between arrest and sentence dropped by two days on January's levels.

The times have been consistently below Labour's 71 day target since October last year.

But Les Thorne, a magistrate in Balham, London, said trials were increasingly been put off for "frivolous" reasons amid a "myriad of excuses".

Only about three in 10 trials went ahead when they were first scheduled, Mr Thorne told BBC Radio 4's Today programme.

Lord Warner, chairman of the Youth Justice Board, told the same programme that delays had been halved in many areas outside London.

Court 'game'

"I would not want to castigate the whole system because of problems in London," said Lord Warner.

He acknowledged some young offenders now saw the courts process as a game.

Defence lawyers were to blame for some delays but prosecution lawyers also did not always have their cases ready in time, he said.

Lord Warner continued: "We want to see more of the people who represent youngsters in youth courts to be actually specialist, trained lawyers who understand the system."

The best interests of some defendants was for their to go into the care of youth offending teams, he added.

The latest figures also show falls in the overall time from arrest to sentence in magistrates court - down to 60 days in February, a cut of four days on the previous month.

But the figure for crown courts rose eight days on January's figures to 170 days between arrest and sentence.