Britney Spears‘ sons are reportedly going to be tested for drugs - but for once it’s not Britney being accused of bad parenting.

Britney’s own legal team are said to have asked for two year old Sean and one year old Jayden to be tested as the star is convinced that ex-husband Kevin Federline has been smoking marijuana around them.

The boys are in sole custody of Kevin at the moment but according to Life & Style magazine, Britney plans to take a snip of each of the boys’ hair next time she has a visitation with them to check whether they have been exposed to the drug.

An addiction expert told the magazine: “Testing for secondhand marijuana use can be done using a lock of hair.”

“The test must be done within a day or two after exposure. Secondhand smoke would definitely show up, and results usually come back in a couple of days.”

But if she wanted to use the tests as evidence in their ongoing custody case, she would have to get permission from a judge - or consent from Kevin - before carrying out the tests.

Britney herself undergoes court-ordered twice-weekly random drug tests - which her lawyers claim have all be returned negative - but a source close to Kevin told the magazine that Kevin isn’t so clean: “Kevin smokes a lot of pot. But he never smokes around the kids.”