US singer Lady Gaga took a moment during her Amsterdam show on Monday night to adopt that old adage - 'When in Rome', seemingly lighting up a marijuana joint given to her by an audience member.

Sifting through gifts thrown onstage by fans, Gaga is seen opening a pack of cigarettes, sniffing each one individually, before throwing them away with a dismissive 'No!'. A kind fan then throws up what looks like a prepackaged joint. Declaring 'Oh, it's real!', after a quick sniff, Gaga sparks up the doobie, exclaiming 'Fucking hell!', after her first puff.

The minx then declares, "That is not nearly enough to get me high!', before tossing the still-lit article into the crowd.

Moments later, as she sits at her piano-motorcycle (yep, you read that right), Gaga continues, "I will one day be meeting with the President, and talking to Oprah the next day.. about the medical wonders of marijuana."

The drug is of course legal in the Netherlands, although a ban on selling cannabis to tourists in coffee shops was suggested last year. Watch this space...