LONDON: Britney Spears is cleaning up her raunchy Circus tour as it heads to Australia - the pop superstar is demanding regular drug and alcohol tests for her employees.

The Toxic hitmaker is heading Down Under in November (09) to play her first ever shows in the country for fans in Sydney, Melbourne, Brisbane, Adelaide and Perth.

And in a bid to ensure she maintains her shared custody of her two sons with ex Kevin Federline while she's on the road, Spears has vowed to stay away from any temptations - and insists her staff do the same.

A source tells Aussie newspaper the Herald Sun, "Britney's rule is clear - zero tolerance. No drink. No drugs. If you do not comply, you do not tour with Britney."

According to the publication, all 150 members of Spears' tour entourage have signed contracts which state they must undergo urine tests.