An investigation has been launched into claims former Guns N' Roses guitarist Slash broke the law by smoking on stage during a concert in Cardiff.
Slash with ash: the guitarist smoking on stage in Germany
Slash and singer Scott Weiland, members of rock band Velvet Revolver, are said to have smoked cigarettes at Cardiff International Arena.
Smoking in enclosed public spaces has been banned in Wales since 2 April.
Cardiff Council said it was "disappointed" to hear the claims and would be investigating.
Velvet Revolver - made up of three ex-Guns N' Roses members and former Stone Temple Pilots singer Weiland - were performing at the city centre venue as part of a tour of Europe and the Americas.
Slash - known for sporting his signature top hat with a cigarette hanging from his mouth on stage - was said to have lit up about halfway through the band's set.
Gavin Allen, who reviewed the concert for the South Wales Echo, said: "I don't think anyone in the crowd minded and I didn't hear anyone complain. It's possible the fans didn't realise it was illegal.
"I'm not that surprised because with a band like that, you expect them to smoke fags."
Since the smoking ban in Wales was introduced, anyone caught smoking in smoke-free premises faces a £50 fixed penalty fine.
There are similar bans in Scotland and Northern Ireland, and England will follow suit on 1 July.
If the case is prosecuted and someone is convicted in Wales, the fine can rise to up to £200.
The manager of a smoke-free building can be fined a fixed penalty of up to £2,500 for failing to stop someone smoking.
Cardiff Council said: "The no-smoking ban seems to be operating well in Cardiff so we are disappointed to hear that there may have been an incident of someone smoking on the stage at the CIA.
"We have yet to receive any formal complaints but we will be investigating the matter and arranging to meet with the management of the CIA urgently to explain that this kind of behaviour is not acceptable as well as seeking assurances that this will not happen again."
No-one at the Cardiff International Arena was available for comment.