Could a picture of Truman and UFO author Frank Edwards I obtained through a friend of my grandmother be further evidence of his interest? It is hard to say seeing as how Edwards was also a newsman and I don't know the circumstances of their meeting. I also don't have any idea if Truman was fully aware of who Edwards was, or his UFO research. I no longer own the picture, but while I did I shared it with the world via the internet, it can now be viewed HERE.
Update: Grant Cameron Showcases Picture I Brought to the Limelight of UFO Investigator Frank Edwards and President Harry Truman
This is an autographed photo of Harry S. Truman and Frank Edwards, a 1950's UFO author, taken in 1954. Frank also used to write for Fate Magazine. It was given to me by a friend of my grandmother because of my interest in UFOS. Kind of makes you wonder.That is what I had to say about Edwards back in 2007. Here is some information and material I only came across recently.
--John T.
http://www.coasttocoastam.com/photo/view/truman_and_the_ufo_author/43569
Before the 1967 Congress of Scientific Ufologists, Gray Barker,
the chairman, received two letters and one phone call telling
him that Frank Edwards, the noted radio newscaster and champion
of flying saucers, would die during the convention. One day
after the meeting was convened there was an announcement that
Frank Edwards had succumbed to an "apparent" heart attack. How
could anybody know that Edwards was going to die, unless it was planned?
http://ufoupdateslist.com/2003/jul/m10-009.shtml