The lawyer for a Serbian basketball player wanted on assault charges in the United States is demanding a halt to a Serb-based investigation into the attack.

Borivoje Borovic says his client, 22-year-old Miladin Kovacevic, can only be prosecuted in Serbia if the Americans formally hand over the case.

Serbia has detained Kovacevic for 30 days pending an investigation into allegations that he inflicted "life-threatening bodily harm" on fellow-student Bryan Steinhauer in a bar fight in upstate New York in May.

Borovic asked Friday that the court end the investigation.

Serbia says its laws ban extradition.