Britney Spears' former bodyguard is ready to support claims of the star's erratic behaviour and drug use in the ongoing child custody battle with her ex-husband Kevin Federline, BBC reported on Tuesday.

Tony Barretto arrived in court in Los Angeles to testify at the hearing but was unable to give evidence before lawyers held debates in a closed session.

"Our client was prepared to testify on issues of nudity by Ms Spears, drug use and safety issues involving the children," the guard's lawyer explained.

The former husband of the pop icon has officially demanded the full custody over their two sons, Sean Preston and Jayden James, in the middle of August.

The divorce of the pop princess with Kevin Federline was finalised in July.