ANTÔNIO.

Vilas-Boas described being left alone in a small room into which a small, blonde, humanoid female with high cheekbones and pale skin was introduced. He reported a sexual encounter — described in his account as initiated by the female — after which she pointed to her belly and then to the sky in what he interpreted as an indication that she would bear a child elsewhere. He was then escorted from the craft, which departed at speed. The entire encounter was estimated to have lasted approximately four hours.

Vilas-Boas reported the event to journalist José Martins, who referred him to Dr. Olavo Fontes of the National School of Medicine in Rio de Janeiro. Dr. Fontes conducted a thorough physical examination and found unusual scars on the witness's chin (consistent with the alleged blood sample), as well as elevated indications of low-level radiation exposure. Dr. Fontes documented his findings in a detailed case report submitted to APRO (the Aerial Phenomena Research Organization). The case was largely unknown outside Brazilian UFO research until APRO published an English-language summary in the mid-1960s.

The Vilas-Boas case is historically the first detailed humanoid-contact abduction account in the modern public record. It precedes the Betty and Barney Hill case by four years. Researchers including Jacques Vallée have noted the Vilas-Boas account contains structural elements — paralysis, medical examination, controlled environment — that would later become recurrent in subsequent abduction reports. The case rests on a single witness with corroborating medical findings.