Police hunting an armed gang who stole 53 million pounds in Britain's biggest robbery questioned six people on Wednesday and continued to search an isolated farm near to the security depot where the cash was stolen, Reuters reported. Kent Police refused to comment on media reports that a substantial amount of money had been found buried on the farm, although police sources have said two of the people in custody are understood to be connected with the property. Overnight, Kent Police stopped more than 600 cars at road checks at four locations linked to the crime when six robbers, posing as police officers, kidnapped the manager of the security depot. The gang also took his wife and young child from their home and held all three before making off with the cash. Senior police officers continue to characterise the investigation as fast-paced and say they are confident of catching the gang. Police on Tuesday recovered what they believe was the white Renault lorry used in last week's raid on a security depot in Tonbridge last Wednesday.