A gang of Cricklewood burglars, responsible for one of London's biggest break-ins and 50 burglaries in Barnet every week at its peak, were jailed this week.

Gerrard O'Leary, the leader of the group, broke into a The Bishops Avenue mansion in January this year, stealing £2.1million of sports cars, jewels and cash. He was jailed at Harrow Crown Court on Thursday for seven years.

O'Leary, along with his gang of burglars, including juveniles who he expertly trained, targeted salubrious homes. Police believe the gang was responsible for 40 per cent of all break-ins across north London over two years.

In a night raid on the home of a wealthy Russian, the 23-year-old Irish traveller and two accomplices stole £1.7million in cash and Cartier jewellery, as well as two sports cars worth £400,000, O'Leary, of no fixed abode, managed to avoid detection as the gang left 'absolutely no forensic evidence' during the crimes, according to police. When O'Leary was finally arrested, three days after the £2.1million heist, he gave police 35 different aliases and 30 different dates of birth.

Around 20 members of the tight-knit Irish Cricklewood traveller community sat in the public gallery as seven members of the gang were sentenced at Harrow Crown Court.

Judge Greenwood said: "You Gerrard O'Leary are only 23. You have an appaling record which includes a number of burglaries. You led and influenced others in the commission of these offences.

"The goods taken were of very high value and the loss was considerable. All of the defendants were very close in terms of personal relationships and geography."

His sister, Louise O'Leary, 29, of Garth Road, Cricklewood, was the only literate member of the family and was said to be crucial in handling the stolen cash. Police found £100,000 at her home and keys to the two stolen cars.

After being sentenced to four years in jail, she rushed across the dock, screaming 'I got more than you' at co-defendant John Sheehan, 43, of Richborough Road, West Hampstead, who was also jailed for four years. She then chased Sheehan down the corridor and kicked and punched him, for which she was sentenced to an additional six months for contempt of court. Sheehan was charged with conspiracy to handle stolen goods.

A 15-year-old boy, who cannot be named for legal reasons, was given a two-year detention order, for conspiracy to burgle, while another 16-year-old boy was given an 18-month detention order for conspiracy to handle stolen goods.

Valerie Bennett, Gerrard's girlfriend, of no fixed address, was given a one-month sentence, suspended for 12 months, also for conspiracy for handling stolen goods.

Detective constable Reg Pickering, of Barnet Police, said: "This was one of the biggest burglaries in London for a good number of years - longer than I can remember. The investigation started after we noticed a surge in the number of burglaries, especially in the areas surrounding wherever Louise was living at the time. They recruited juveniles and trained them in the art of committing burglary and in not being caught."

Police believe the gang may have been sending money to Ireland and investing money in property worth hundreds of thousands of pounds . A confiscation hearing is set for September.