Police raided the lab of José Ramón Báez Acosta after receiving complaints from former patients.

Investigators seized samples of the formula dubbed ''Uman TS,'' medical equipment, and two pigs and a donkey that Baez Acosta was apparently using for tests.

Last week he told he had cured 52 people of AIDS and that God revealed the treatment to him in a dream.

Pan American Health Organization representative Ana Cristina Nogueira said Thursday that public health officials should track down AIDS patients who may have been hurt by the serum or who stopped other treatments because they believed they were cured.

''Every now and then these people appear saying there is a cure,'' she told the Associated Press. ''It is difficult to control that when it goes out in a newspaper.''

Báez Acosta was not arrested or charged, but prosecutors are investigating with the aim of bringing him to trial.

Health officials ordered an immediate stop to the treatment.