British police said Monday that thieves stole $92 million during last week's heist at a security warehouse — the biggest cash theft in the country's history.

Warehouse owner Securitas had confirmed the total after an audit, said Adrian Leppard, assistant chief constable of Kent Police.

The amount eclipses the $50 million stolen by a gang from the Northern Bank in Belfast in December 2004 — at the time the largest amount of cash ever taken in a robbery in the United Kingdom.

Leppard told reporters that four men had been arrested in south London and adjoining Kent county in the last 24 hours and were being questioned in connection with the robbery. A fifth man was arrested and released.