WASHINGTON - The Supreme Court issued a last-minute stay late Tuesday to a Florida death row inmate who claimed he was mentally retarded and should not be executed for killing a police officer.

Florida prison officials had delayed the execution of Clarence Hill, who also wants to challenge the drugs that would be used.

It was not clear if the court's intervention would only briefly delay Hill's execution, which had been scheduled for 6 p.m. EST. Justices were reviewing a pair of Hill appeals, and Justice Anthony Kennedy filed paperwork that said the execution should be delayed.

Earlier, Hill had lost appeals at the 11th U.S. Circuit Court of Appeals in Atlanta. He was scheduled to die at Florida State Prison for the Oct. 19, 1982, slaying of a Pensacola police officer and the wounding of his partner.