Many cheap online travel deals are not what they seem, and several 'household name' websites are among those making misleading claims, according to a survey carried out by the Office of Fair Trading (OFT) last week.

The OFT checked 135 UK travel websites at random, and found that 40 per cent of them made deceptive, misleading or false claims. The companies could now face prosecution.

Among the claims made on the websites were:

· 'hot deals' on a front page which bear no resemblance to the prices actually available on the website;

· an advert stating 'Australia from £599' when the cheapest price was £891;

· an offer of seven nights in Austria in March for £99, when the cheapest price was £259;

· a claim of 'up to 70 per cent discount off worldwide hotel rooms' with no further mention of any savings or discounted deals;

· a special offer of £64 per person per night with certain conditions when it couldn't be booked for less than £128.

John Vickers, OFT chairman, said: 'The internet is an expanding resource. Online shoppers must have the same protection afforded by the high street, and if traders breach fair-trading law, the OFT will pursue them.'

Local trading standards authorities are now investigating the companies involved and will either negotiate undertakings to change or seek court orders to ensure they stop breaching regulations.

An OFT spokeswoman said: 'If you think of the first 10 names that come to mind selling flights, holidays and days out, we will be investigating quite a few of these. People tend to think a giant household name must be shipshape, but our work in the past has proved this isn't always so.'

The OFT has spent two years negotiating with the big four travel companies Thomson, Airtours, First Choice and Thomas Cook to get their contracts with consumers in line with package tour regulations.

The OFT undertook a 48-hour random sweep of travel sites last week and followed up the claims either online or by phone.

At the same time, consumer protection agencies in another 30 countries carried out similar checks. In total, more than 1,000 problem sites were identified worldwide.