Energy regulator Ofgem is investigating British Gas for allegedly overcharging its customers who wanted to switch to other providers.
While confirming the probe on Thursday (6 July), Ofgem clarified the triggering of an investigation did not imply it had discovered instances of non-compliance.
A spokesperson also said it was too early to comment on the direction of the investigation.
Under current tariff terms, British Gas customers planning a switch to another energy provider before a fixed-term deal expires can do so free of charge for up to 49 days before their deal ends.
However, complaints received by the website MoneySavingExpert, subsequently passed on to Ofgem, allege that British Gas demanded a termination fee of as much as £60 in some cases from those wishing to switch despite the request coming within the stipulated 49-day period.
British Gas said it would co-operate with the Ofgem inquiry.