There are currently two 24 hour off licences in the London Borough of Camden:
Sainsburys, O2 Centre, 255 Finchley Road, Swiss Cottage/West Hampstead, NW3 6LU - 020 7433 1493 (No longer open 24 hours)
Sainsburys Local, Mid City Place, 71 High Holborn, London, WC1V 6EA - 020 7404 9406 (Not currently open 24 hours)
Please Note: Just because a shop is listed as having a 24 hour alcohol licence doesn't necessarily mean that the shop is open 24 hours a day, 7 days a week. It's also worth noting that large 24 hour supermarkets (Asda, Sainsbury's and Tesco) are not open all night on Saturday, Sunday and bank holidays (due to Sunday trading laws in England and Wales).