Concert promoter AEG Live has received a warning from the advertising regulator after a "one-off" Kanye West show was followed by two further tour dates.
AEG Live sent an email offering tickets to see the American rapper, announcing it as "a one-off show at London's Hammersmith Apollo" on February 24.
One person complained that the offer was misleading because two further concert dates in London were subsequently announced.
AEG Live said the Kanye West concerts were "not typical events", and the February 24 concert was arranged and marketed "at extremely short notice and was intended to be a one-off performance".
However, it was decided to put on additional shows in response to demand for tickets.
The Advertising Standards Authority (ASA) acknowledged that AEG had no plans to hold additional concerts at the time the ad was sent. But it said: "We considered the claim "one-off" was likely to be interpreted by consumers who received the ad to mean no other Kanye West concerts would take place in the UK.
"Two days after the email was sent, two further concert dates of February 23 and March 1 were announced and tickets for those concerts went on sale."
It noted that the original ad was for a pre-sale event, which the ASA considered was likely to be seen as conferring an advantage to those receiving the email over other consumers who wanted to buy tickets.
It added: "Because two more concert dates were added which gave consumers further opportunities to buy tickets to attend a Kanye West concert and those dates were announced only two days after the ad was sent out originally, we concluded the claim that Kanye West would perform a "one-off" concert in the UK had not been substantiated and was misleading.
"We told AEG Live not to describe concerts as a "one-off" when there was the possibility that further dates could be added."