Franco Colapinto joked in Las Vegas that he hopes there won't be any anti-doping tests this weekend, given the pervasive aroma lingering around the circuit.

Sergio Perez was the first to raise the issue late on Thursday, as the Red Bull driver noted the distinct smell of marijuana in the air throughout 'Sin City.'

"What is very noticeable around the circuit is the smell of marijuana throughout the night," said Perez. "I'm a bit tired of it already - the amount is incredible. It's something all the drivers will definitely talk about."

Although public consumption of marijuana is not legal in Nevada, the state permits the retail sale of cannabis, which can be purchased at licensed dispensaries and consumed in authorised lounges across Las Vegas.

Williams rookie Colapinto echoed Perez's observation, adding his own humour to the situation. "Yes, there is a smell of weed," he confirmed on Thursday. "If they dope (test) the drivers now, I think we'll all test positive, I swear."