Spears 'furious' at Federline's preferential treatment

Britney Spears is "furious" her ex-husband Kevin Federline has not been required to undergo a drugs test in their ongoing custody battle, according to reports.

Spears lost physical custody of her sons - Sean Preston, two, and Jayden James, one - earlier this month, after reportedly ignoring a string of court-imposed demands and skipping mandatory drug tests.