London: British police charged three people on Wednesday in connection with a £53 million raid on a security depot in southern England, the biggest cash robbery in British history.

The two men and a woman were the first to be charged over last week's heist.

A gang posing as police officers seized the depot's manager then took his wife and young son hostage and threatened to harm them unless he helped them get inside the compound, police said.

The robbery eclipsed the theft in 2004 of £26.5 million from a bank in Northern Ireland that was widely blamed on Irish Republican Army guerrillas.

It also surpassed Britain's most famous cash raid: the Great Train Robbery of 1963 when a gang stole £2.6 million from an overnight mail train.

Police in the southeast county of Kent said the probe could last for years.