'Austin Powers' Villain Victim ID'd in Prison Murder

Thomas Graham
The prison inmate who was allegedly murdered by "Austin Powers" actor Joe Son has been identified ... and authorities tell us he was a convicted child molester.

The victim has been identified as 50-year-old Thomas Graham (pictured above) -- who had once been convicted for committing lewd and lascivious acts on a child under the age of 14.

At the time he was killed, Graham was serving a two-year sentence in Wasco State Prison for failing to properly register as a sex offender.

As TMZ previously reported, cops believe Graham's cellmate Joe Son -- who played shoe-throwing villain Random Task in the original "Austin Powers" movie -- killed Graham in their cell on October 10.

Son is currently in solitary confinement  while prison officials investigate.

Son is already serving a life sentence for torturing a woman back in 1990.