The memo is dated March 22, 1950 and was written by the FBI's Washington, D.C. field office head at the time, Guy Hottel.
The document is freely available via the FBI records vault. It reads:
An investigator for the Air Forces stated that three so-called flying saucers had been recovered in New Mexico. They were described as being circular in shape with raised centers, approximately 50 feet in diameter. Each one was occupied by three bodies of human shape but only three feet tall, dressed in metallic cloth of a very fine texture. Each body was bandaged in a manner similar to the blackout suits used by speed fliers and test pilots.
According to Mr. [REDACTED] informant, the saucers were found in New Mexico due to the fact that the Government has a very high-powered radar set-up in the area and it is believed the radar interferes with the controlling mechanics of the saucers.
No further evaluation was attempted by SA [REDACTED] concerning the above.
According to the FBI, the Hottel memo was first released to the public in the 1970s. Though it is often assumed to be connected to the legendary Roswell UFO crash, the memo is dated almost three years after the Roswell incident.
The agency also stressed that the Hottel memo is not proof of extraterrestrials, in that it refers to a second- or third-hand account that was never investigated further.