The suicide note left by South Carolina lobbyist Tom Sponseller revealed his embarassment over a federal investigation into the business he led and his disappointment in himself.

The note, initially discovered by Sponseller's co-workers and obtained by WIS, seemed to explain why Sponseller may have killed himself.

"It is quite disappointing that all the work our members and staff put into building one of the best associations in the state has been jeopardized," Sponseller's note said, referring to a federal investigation into missing money at the S.C. Hospitality Assocation.

Sponseller said he "failed to make sure everything was right," with the missing money until police had already discovered it.

See all of Patch's coverage of Tom Sponseller's case here.

Federal agents are investigating several hundred thousand dollars that went missing from the Hospitality Association. Rachel Duncan, a former accountant who Sponseller called "like a daughter" to him in the note, is the target of that probe.

Investigators said they did not suspect Sponseller of involvement in the missing money case, but Sponseller's note revealed his personal feelings of guilt.

"I am a huge disappointment to everyone, my family, my friends, business associates and others," Sponseller wrote. "I let everyone down and have embarrassed those who I love the most, my wife, kids, and grandkids."

Sponseller's family reported him missing on Feb. 18, but police did not find his body until Tuesday morning.

Autopsy results released Wednesday showed that Sponseller died "relatively near the time he was reported missing," according to Richland County Coroner Gary Watts.

Watts confirmed that a single gunshot wound to the head caused the death.