Of note here is the fact that the witness was a naval officer.
Night of October 10, 1957:
Spanish Naval officer and mineralogist Miguel Navarrete and his chauffeur were returning from a fishing trip when they spotted a bright light that had began a steep climb into the sky. After finishing the climb the men realized that it was a huge object a few hundred meters in diameter. Its light was so intense that it clearly illuminated the area around the witnesses, even while at a great height.
The driver panicked and tried to drive the truck away from the area. However, the truck's engine stalled and at the same time, the huge object approached, flying over the vehicle hovering at about 40 yards away.
The craft was about 140 meters in diameter and about 40m tall, oval in shape with the top higher than the bottom, like two superimposed plates separated by a band of approximately 20 meters deep. When it was at about 6 meters in height, the light went out and it stopped in midair. It then landed.
Once it landed a large door opened and the witness saw 7 human-like figures, with blond hair and wearing shiny silvery outfits. The aliens exited the object briefly and stared silently at the truck and the stunned witnesses. After returning to the craft the object took off and stopped at about 500 feet in altitude. At this point a smaller object came out of it and flew in a northern direction at high speed.
The larger object then disappeared towards the southeast. After the incident, Mr. Navarrete was interviewed by local magistrate, Dr. Gabriel Barbosa and his deputy Paulo Roberto de Carvalho.
After the interview the judge sent a letter to the Secretary of the Interior and the Head Justice for the state of Goias reporting the incident.
Source: Judge Gabriel Barboza De Andrade & "The Humanoids." Thanks also to researcher Albert S. Rosales for posting the report.
For the previous account see: