Drug testers have swooped on the homes of several Formula One drivers in surprise early morning raids.
Ferrari's dual world champion Fernando Alonso said the testers, from the World Anti-Doping Agency (WADA), arrived at his house at 6.42am on Tuesday (local time).
New McLaren driver Sergio Perez confirmed he had endured a very early morning wake-up call as the result of a surprise urine test.
And Torro Rosso racer Daniel Ricciardo tweeted that he ''Got drug tested early hours this morning.''
He said: ''All of a sudden pissing in your own home becomes difficult with someone staring over your shoulder.''
Drug testing in F1 is relatively rare, but it is not the first time officials have made surprise visits to drivers' homes.
In 2009 Mercedes driver Nico Rosberg - then with Williams F1 - was drug-tested by WADA while on holiday in Ibiza.
He said the agent woke him up at 7am one morning, informing him that he had been selected for random drugs spot-check.
''My girlfriend took the call,'' Rosberg said. ''So it was lucky that the test took place at all because she doesn't like being woken up early while on holiday.''
Mark Webber recently called on Formula One's governing body, the FIA, to step up its drug testing, after a motorcycle racer was banned.
Former MotoGP rider Anthony West, who now races in the second-tier Moto2 category, was banned for a month after testing positive for the stimulant Methylhexaneamine.
Webber welcomed motorcycling's push to ensure the sport is drug-free, and called on the FIA to become more active on the issue.
''I've always been championing the idea to do more of it, but the FIA have never really been that strong on it,'' Webber said.
''The other drivers have never been super strong on it, so it's never really been a huge issue.''
Domestically, V8 Supercar drivers will be drug tested up to three times more often under tougher anti-doping rules to be implemented by motor sport authorities, according to a Fairfax report.
Through CAMS, V8 Supercars complies with the anti-doping requirements of WADA and the Australian Sports Anti-Doping Authority.
Racing drivers have not been implicated in the recent Australian Crime Commission's investigation into drugs and corruption in sport but CAMS will review its approach to anti-doping, illicit drugs and also race fixing and corruption.