A Spanish judge will ask the United States if it plans to probe alleged torture at the Guantanamo Bay detention camp before deciding whether to open his own inquiry.

Judge Eloy Velasco from Spain's top criminal court will make the request formally in a letter to officials in the United States, according to a copy of the document obtained on Tuesday.

The National Court is considering a complaint filed on behalf of a rights group that alleges that six officials in the administration of former president George W. Bush sanctioned torture against prisoners at Guantanamo Bay.