The Office of Fair Trading is giving special attention to its formal investigation into the hotel business. It is looking at allegations of price-fixing in the sale of hotel rooms over the internet.
One website offering hotel rooms had reported that it was being put under pressure to offer them to guests at a pre-set price.
It claimed that hotels would phone, email and threaten legal action to get its prices raised. The danger is that customers could end up paying more than necessary.
The OFT stated this week the matter is an "administrative priority" and it is pursuing the investigation further, saying that it needed to obtain and assess additional evidence.
The sale of hotel rooms online has become a huge business, dominated by big hotel groups and a handful of global websites.
The Office of Fair Trading is looking at suspected breaches of competition law. This is thought to include allegations of concerted practices resulting in fixed or minimum prices.