Hotel group Yotel has expressed "keen interest" in purchasing a system of London underground tunnels, used as air raid shelters in World War II, after they were put on the market for an estimated £5m.

The Kingsway Tunnels, built in 1940, are located 100 ft beneath central London and were put up for sale by its current owner BT. They immediately evoked interest from Yotel for a future leisure and hotel complex.

Yotel intends to transform the mile-long network of tunnels into an underground destination featuring its trademark pod-style hotel with a lounge, a bar and a club. The company currently operates its hotels inside terminal buildings at Heathrow and Gatwick airports.

The system of horizontal and vertical shafts run directly beneath High Holborn and have previously been used by MI6 and to hold 8,000 people during the Blitz. It was also used as a public record library and as a telephone exchange that linked the presidents of the USA and the USSR during the Cold War.

Yotel founder Simon Woodroffe, said: "The quantum leap in developing Yotel was to position the windows to face the corridors, which means that we can go where others can't. If we had done market research on this concept I don't think we'd have had a thumbs up but the most common customer response today is 'why hasn't it been done before?'"

BT has owned the 77,000sq ft (7,153 sq m) site since 1986 and had tried selling it in 1996, but with little success.

As reported in the Guardian newspaper BT said that the planning restrictions for the tunnels would rule out "a smart new hotel, home or office" as there is only one entrance, and that BT has received a number of expressions of interest in the tunnels.