Petrol and diesel review launched by OFT
5 September 2012 Last updated at 13:07 BST
The UK petrol and diesel sector is being put under the microscope by the fair trading watchdog amid rising prices at the pumps.
The Office of Fair Trading (OFT) will spend six weeks gathering evidence about whether competition is being curtailed.
The watchdog will also consider whether falling costs of crude oil are reflected in prices paid by motorists.
Senior director of the OFT Ann Pope told BBC News that action could be taken against the entire industry or individual businesses.