A gang of up to 10 people attacked and robbed a man by the entrance to North Gate Bus Station.
Police revealed this morning that the attack happened on the junction of Bradshaw Street and Drapery, some time between 6.40pm and 7.20pm last Thursday, October 27.
The victim saw another man being kicked on the floor and when he tried to intervene, he was set upon by the gang, who punched and kicked him to the floor before making off with a quantity of cash.
All the gang members were described as male and black.
Anyone with information can contact Northamptonshire Police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.