Belgrade - Serbia's war-crimes court said Friday it had launched an investigation into a US citizen suspected of committing war crimes while serving as a Nazi officer in Belgrade during World War II.

The court said in a statement that 86-year-old Peter Egner was suspected of committing genocide and war crimes against civilians in Belgrade from 1941 until 1944.

In July, US authorities took legal steps to revoke Egner's citizenship saying he concealed his service in a Nazi unit that killed thousands of civilians in a Belgrade death camp after moving to the US in 1960.

US prosecutors allege that Egner, born in the former Yugoslavia, volunteered for a Nazi-controlled police unit that killed 17,000 civilians - mainly Serbs, Jews and Roma - at the Old Fairgrounds on the banks of the Sava river.

Serbia said it would ask the United States to extradite Egner, who became a US citizen in 1966.

If the US revokes Egner's citizenship, he could be extradited to Serbia.

Egner, who lives in a retirement home in Bellevue, Washington, denies any involvement in killing civilians. (dpa)