Palacio, in Britain to defend his title against John Davison, of Newcastle, on Saturday, failed the test in Sunderland on Tuesday and was subsequently refused permission to box by Alan Trotter, a British Boxing Board of Control doctor.
According to Ed Levine, the president of the WBO's championship committee: 'The doctor's report indicated the presence of the HIV virus, and on that basis we had no alternative other than to declare the title vacant.'
Palacio, who took the title from the Londoner, Colin McMillan, last year, was subjected to two tests. 'We had to make absolutely certain of the initial findings, so he was tested again yesterday,' the promoter, Barry Hearn, said. 'Unfortunately for Palacio, the second test confirmed that he is indeed infected with the HIV virus.'
The WBO supervisor, Mark Schechner, speaking in Rome last night, confirmed Palacio had been stripped of his title. But the 34-year-old Davison will still be able to fight for the title on Saturday - against a last- minute substitute, Steve Robinson, of Wales. The WBO was unable to find one of its top-10 ranked fighters to step in at 48 hours' notice, though Schechner said it had sanctioned the 24- year-old Robinson's challenge.
Robinson is the WBA Penta- Continental champion. The contest for the vacant world crown will be held at the Northumbria Centre in Washington, Tyne and Wear, on Saturday night. The fact that the contest is going ahead is a relief for Davison, who has been lined up to fight for his first world title on three previous occasions, only to have each of the contests postponed.
'This fight with Palacio seems to have been fated from the start,' Davison said. Palacio, who relieved McMillan of the title in September, had twice previously pulled out of defences against Davison this year. First, he underwent a hernia operation and then he had Achilles' tendon problems.
In February 1990, the Zimbabwean heavyweight, Proud Kilimanjaro, was prevented from competing in a bout against Lennox Lewis at Crystal Palace because he refused to give details of an Aids test to the British Boxing Board of Control.
Boxing's first Aids-related death was Esteban De Jesus, the former world lightweight champion from Puerto Rico, who reigned briefly in the early 1970s.
Sergei Artemiev, the Russian boxer who had a blood clot removed from his brain after a fight last month, was released from hospital in Atlantic City yesterday. Artemiev returned to his home in New York where he will undergo rehabilitation.