A US Army soldier serving in Afghanistan who allegedly watched his wife have sex with a 15-year-old girl over Skype, has been charged with child sex abuse.

Shawn Raymo, 22, and his wife Jessica Raymo, 21, who both live on the Fort Drum army base in Upstate New York, were arrested on Tuesday on charges of endangering a child's welfare, and of using a child in a sexual performance.

The alleged crime took place while Shawn Raymo was deployed in Afghanistan in July 2011.

Mrs Raymo is alleged to have had oral sex with the teenage girl while her husband watched via a webcam.

Mr Raymo, who returned from deployment in last Autumn, was arraigned in court and held in jail on $5,000 bail along with his wife - after the charges recently came to light.

A spokesman for Fort Drum told the New York Daily News this was the first time he had heard of sex crimes happening involving soldiers at the US Army post before.