Travis Barker and ex-wife Shanna Moakler are reportedly being investigated by child protective services.

Police contacted the Los Angeles County Department of Children and Family Services after the former couple, who have two children, Landon, 11, and Alabama, nine, were arrested for threatening to kill each other last month.

The Blink-182 drummer and the former Miss USA beauty, who split in 2008 after four years of marriage but still live together, were both taken into police custody on December 7 after they got into a verbal fight over a reality TV show Travis wants to do with their children, according to court documents obtained by gossip website TMZ.com.

Shanna, 39, who is now seeking to have their custody agreement changed, claims she called the police because her ex-husband said: ''If I could, I'd put a bullet in your head.''

The blonde beauty is concerned that Travis has been displaying erratic behaviour since he survived a plane crash in 2008 and alleges he has been verbally abusive towards her, calling her ''a cigarette smoking, coke-snorting b**ch.''

But the rocker, 39, claims Shanna threatened to get her current boyfriend to come over and beat him up.

Law enforcement sources said no charges will be filed against Shanna or Travis, but child protective services were contacted and are investigating the incident.