Tesco has come up with a new concept to boost its grocery offer - but it is a store that customers will never be allowed to enter.

The first Tesco.com-only store opened in Croydon, south London, in February.

Although from the outside it looks like a warehouse, the inside of the building is laid out exactly like a supermarket with the same fixtures and fittings that would be found in any store.

It enables people in the area, who previously didn't have a local Tesco with the capacity for store-picking, to have access to online shopping from Tesco for the first time.

Creating it in a supermarket format was essential, said finance director Andrew Higginson, as Tesco uses a store-picking order system.

The concept was unveiled this week by Sir Terry Leahy, who said this approach had already proved highly effective in Croydon, adding that the format would only be used selectively around the country.

The launch comes as Tesco prepares to unveil a home-shopping offer for non food, which is expected to be pitched against the likes of Argos.

Sir Terry confirmed it would initially focus on hard lines, such as furniture and electronics, but a decision had not been made about creating an online clothing store. Tesco has been developing its non-food distribution network for the past year, including a non food-only warehouse that recently opened in Daventry, Northamptonshire.

Sir Terry said that the majority of Tesco customers did not have access to its full non food offer. "The potential is huge. We would like to put non food in front of more people more quickly."

The launch is expected to happen later this year, but it won't be before the World Cup, he confirmed.