The council is to investigate whether Keith Richards smoked on stage

The city council confirmed it was investigating reports that he smoked on stage throughout the gig on Friday.

The veteran rocker could face a �50 fine and Hampden Park could also face a �250 penalty if officials prove the venue failed to enforce the ban.

The rock 'n' roll legends are on the UK leg of their A Bigger Bang world tour.

A ban on smoking in all public places came into effect in Scotland on 26 March this year.

Hampden Park had introduced its own smoking ban three months before the nationwide ban was introduced.

At the beginning of this month, actor Mel Smith was warned not to smoke during his performance of Churchill in the play Allegiance at the Edinburgh Fringe festival.

If he has been breaking the law then he has to pay the penalty like anyone else Maureen Moore Ash Scotland

Edinburgh City Council had said that the Assembly Rooms would be shut down if the law was broken.

Neil Rafferty, from the Freedom Organisation for the Right to Enjoy Smoking Tobacco (Forest), said: "This is yet another way in which the smoking ban makes Scotland look ridiculous.

"A few weeks ago we had Mel Smith being forced to compromise his portrayal of Winston Churchill under a threat of the whole venue being closed down, and now we have Scotland's national stadium Hampden Park under investigation for spurious reasons."

However, the anti-tobacco organisation Action on Smoking and Health (Ash) Scotland said celebrities should not be above the law.

Chief executive Maureen Moore said: "The law in Scotland says where you can and cannot smoke and it's been brought in to protect workers and the public from a Class A carcinogen - passive smoking.