The Advertising Standards Authority has upheld another two complaints against MyCityDeal Ltd – which trades as Groupon – taking the total for 2011 to 15.

Both the latest complaints claimed that Groupon promotions for go-karting activities exaggerated the saving available.

In one, which offered 50 laps around a track for £15, the claimed saving was 67%. In the other, for exclusive hire of a track for a whole day for up to 300 people for £1,500, the claimed saving was 63%.

The complainant, another go-karting operator, argued the value of the experiences on offer had been exaggerated and therefore the ads were misleading.

The ASA ruled that both promotions were misleading, and told Groupon not to run them again in their current form.

The latest upheld complaints come less than a fortnight after the Office of Fair Trading revealed that it had launched an investigation into Groupon’s business practices and the ASA announced that it would be sending consumer complaints about the deals website directly to the OFT.