Lead investigator in 'American Sniper' Chris Kyle murder case found dead from gunshot wound
Navy Seal Sniper Chris Kyle signs a copy of his new book 'American Sniper' on Jan. 13, 2012 (U.S Marines photo)

One of the lead investigators in the murder of "American Sniper" Chris Kyle was found dead from an apparent self-inflicted gunshot wound.

Tommy Bryant, the Erath County sheriff, was found dead late Monday night at his home, reported the Stephenville Empire-Tribune.

The sheriff helped investigate the February 2013 fatal shooting of Kyle, a former Navy SEAL sniper whose memoir was turned into a blockbuster movie, and his best friend, Chad Littlefield, at a gun range.

A troubled former U.S. Marine, Eddie Ray Routh, was found guilty of capital murder two years later.

Bryant's death comes less than one week after denying reports that he was under investigation by the Texas Commission on Law Enforcement for allegedly cheating on his continuing education training.

"I don't know of any investigation against me and I don't know why there would be one," Bryant said. "I have done nothing wrong."

Bryant, who in 1997 unseated longtime sheriff David Coffee, was re-elected in March after receiving nearly 70 percent of the vote in a Republican Party primary.

U.S. Navy records show Kyle embellished his military service record.