Just half of close contacts given to England's NHS Test and Trace are being reached in some areas, a BBC investigation has found.

Six months after Boris Johnson promised a "world beating" system, it can be shown the network is failing in areas with some of the worst infection rates.

The research also found no-one from NHS labs was at a key government meeting with private firms about testing.

https://www.bbc.co.uk/news/health-55008133

See all the names in the graphic.

But the government said the system was "undoubtedly" curbing Covid spreading.