
Seventeen million British Gas customers are facing higher bills after the firm raised its gas and electricity prices.
The UK's biggest energy supplier will raise gas and electric prices by 22% from 1 March 2006.
The firm blamed the price hike on substantial rises in wholesale gas prices, up about 70% since September.
On Thursday, the European Commission said some European energy firms were holding back gas supplies, driving up prices of imports into the UK.
The findings of an investigation into the gas and electricity sectors have prompted Brussels to launch a crackdown on anti-competitive behaviour.
Without naming companies at this stage, EU competition boss Neelie Kroes said a number now faced separate probes.
British Gas, which is part of the Centrica group, warned last December that energy prices would have to rise.
The group raised its prices by 14% last September, since then estimates suggest that the price of wholesale gas has risen by about 70% since last September.
British gas has a 55% share of the gas market and 23% of electricity. It has eleven million gas accounts and six million electric.
In the past few days, both EDF Energy and Scottish Power has raised their prices.