Mobile phone users are being warned not to buy unbranded and unmarked replacement chargers over the internet or from shops or market stalls, following safety fears.

Tests by Lambeth Council trading standards and the Electrical Safety Council on cheap mobile phone chargers for sale online and in south London shops and markets found the majority did not meet safety standards, and could potentially cause electric shocks or overheat and catch fire.

The eight main branded chargers met safety standards, but a catalogue of faults were identified in 14 out of the 15 unbranded devices.

Faults included unsuitable electrical insulation.