A week after he was charged in an elaborate scheme to defraud state taxpayers, a former

University at Buffalo researcher was found dead Tuesday afternoon in his Eden home, but

authorities have not determined a definitive cause.

"I was told that it was natural causes," a family friend said Wednesday of the death of

William Fals-Stewart, 48.

Other sources said that an autopsy performed Wednesday found no definitive cause of death

and further tests are planned.

"We don't know what the cause of death was," Eden police Investigator Shawn Bishop said

Wednesday morning, before the autopsy had been completed in the Erie County medical examiner's

office. Eden police could not be reached to comment later.

Fals-Stewart had been accused of using actors to portray witnesses who testified on his

behalf at a formal misconduct hearing.

The testimony from the bogus witnesses enabled Fals-Stewart to be exonerated, State

Attorney General Andrew M. Cuomo has said. The researcher later attempted to sue the state for

$4 million, claiming he had been wrongly forced out of his job.

Fals-Stewart was arrested Feb. 16 on multiple charges of attempted grand larceny, perjury,

identity theft, offering a false instrument and falsifying business records, all felonies.

Authorities claimed that Fals-Stewart engaged in the fraudulent conduct in an attempt to

rescue his reputation after leaving his UB job, under pressure, in 2005. Officials have said

he had been accused of scientific misconduct by fabricating data in a federally funded study.

Police went to Fals-Stewart's Knoll Road home Tuesday in response to a first-aid call,

after a relative found him unresponsive on the couch.

"We performed [cardiopulmonary resuscitation]; it was unsuccessful, and it was [considered]

an unattended death, so our policy is that we do an autopsy," Bishop said.

Bishop wouldn't comment further on the possible cause of death.

The family friend, though, said that people close to Fals-Stewart believed he had been

seriously ill in recent years.

"It's very difficult to have a person taken away at such a young age," the friend said.

"He was a good family man who loved his wife and children and fought to the end for them,"

the friend added. "It's very tragic. It's very sad to watch his wife and children and friends

go through this."