Two Lake County sisters are under federal investigation after officials said they were suspected of collecting their dead father's Social Security checks for years.

Deputies said the pair confessed that their father died five years ago, and they panicked and buried him in the back yard of his Eustis home on Parkcrest Drive.

A case file against Susan Kort and Sarah Kort for improper disposal of a deceased body has been sent to the State Attorney’s Office.

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The body of 94-year-old Merlin Kort was found in a shallow grave in September, officials said.

Many neighbors, including Jamie Osborne, said they were “very shocked.”

Investigators said many relatives had not talked to Kort in a while and were concerned.

"The sisters stated that he moved up north, and that he was staying with relatives," said Fred Jones of the Lake County Sheriff’s Office.

Deputies said they later got a tip that Kort's body was buried on the property, which was fenced and covered with trees.

Deputies said they believe Kort’s body had been there between four and five years.

"I never knew he lived back there," said Osborne.

Deputies said the sisters claimed he died of natural causes, but instead of calling to report it "they panicked and they didn't know what to do and so they buried his body in the back yard."

But no one knew Kort was dead. Mail continued to be delivered to Kort's home, which included his Social Security checks.

The U.S. Inspector General's Office has not returned WFTV’s call for comment.

"Yeah, and to be your father, you don't do that. You just don't treat your father like that," said Osborne.

Deputies said the sisters said Kort had health issues.

Investigators said they did not find anything that leads them to suspect foul play.