New blow for Britney as she 'fails' drug test

Britney Spears has failed a drugs test, it was claimed today.

The result could be a massive blow to her custody battle.

The troubled singer has been ordered by an LA court to undergo mandatory testing but her ex-husband Kevin Federline claims Britney has ignored eight out of the 14 random tests.

Violation: Britney is reported to have failed a drug test but her people deny the report and said it was a 'false reading'

A source close to Britney, 25, revealed today that one of her drugs tests has come back positive, but the source claims that she actually passed and the result was a false reading.

The couple are due back in court on Wednesday to discuss their ongoing custody battle over sons Sean Preston, two, and one- year- old Jayden James.

Under the latest court ruling, Spears is allowed to see the boys three times a week, but must follow an earlier order to undergo mandatory drug and alcohol tests and attend parenting sessions with Federline.

Blues for Britney: Britney is due back in court on Wednesday to discuss the ongoing custody battle over sons Sean Preston, two, and one- year- old Jayden James

But K-Fed's lawyer, Mark Vincent Kaplan, claims Britney has violated the court drug test order by ignoring eight out of a total of 14 requests and lives in a "parallel universe".

He told the court: "Mr. Federline doesn't want to take these children out of their mother's life, but what are we to do?"

The moment Britney was caught on camera jumping a red light while using her mobile

However, Spears's new lawyer, Anne Kiley, has defended the star's actions and branded the drug testing procedure "unconstitutional".

Meanwhile, it has also been reported that Britney drove through a red light and was texting on her mobile phone while her two sons were in the back of the car.

Federline's lawyers have already asked the judge to ban Britney from driving with the children in the car, but this development could accelerate that decision.

Serial offender: Britney was driving around with her sons and a court appointed parental monitor when she committed the offence

In early 2006 she was investigated by child welfare authorities after being photographed driving with infant Sean Preston on her lap rather than in a child seat.

Last month she pleaded not guilty to driving without a valid driving licence, and has since obtained a California permit.

In August she hit a parked car outside a shop, but hit and run charges were dropped after she paid the driver for the damage.

She has also been photographed parked in a disabled bay, and last week she was under investigation after running over a woman sheriff's deputy's foot as she drove away from the downtown Los Angeles courthouse.