Radisson, Thistle and Starwood have been named by the Daily Telegraph as the hotels under investigation for alleged price fixing with online travel agencies.

The Office of Fair Trading began an investigation last year into alleged price fixing between leading hoteliers and online travel retailers to prevent heavy discounting on rooms.

The investigation followes allegations that retailers offering prices below agreed rates are refused access to rooms.

The Daily Telegraph report, which claimed to have seen leaked document relating to the investigation, named the Radisson, Thistle and Starwood groups as among those under investigation for involvement in a system of “rate parity” agreed with online agents. The OFT said the investigation was at “a relatively early stage”, but adding that the issue was “an administrative priority”.

Previous OFT investigations have resulted in heavy fines, with British Airways paying £121 million for colluding on fuel surcharges on fares in 2007.

However the OFT is under pressure to justify its role with the government insisting on merging it with the Competition Commission. A tribunal last month slashed fines imposed by the OFT on six construction-industry firms by 90%, and BA has said it will seek repayment of its fine.

The complaint to the OFT is understood to have come from hotel review and booking site Skoosh.