The Metropolitan Police Act of 1839 gave greatly increased powers to the Metropolitan Police.
The district over which it operated was increased to cover a 15 mile radius from Charing Cross.
Constables were given ‘all powers and privileges’ in the counties of Berks, Bucks and on the River Thames.
Within the Port of London they could now inspect vessels to prevent smuggling, to seize loaded guns and unlawful quantities of gunpowder.