SALT LAKE CITY -- A federal grand jury indicted a Utah man Wednesday afternoon in the investigation of ricin, a deadly poison found in a Las Vegas motel room.

Thomas Tholen, 54, was indicted on a charge of misprision of felony, or failure by a person not an accessory to prevent or notify the authorities of a felony, reported KVVU-TV in Las Vegas.

U.S. Attorney Brett Tolman said the Riverton, Utah, man knew that biological agent ricin had been produced -- a federal felony -- but did not report it to federal authorities.

The indictment also alleges Tholen concealed the crime by providing an untruthful statement to authorities, concealing his knowledge.

"Today's indictment is very straightforward," Tolman said in a news release. "It alleges Mr. Tholen knew about the ricin, knew it has been produced in violation of federal law and did not report it to authorities. Furthermore, when law enforcement authorities found out about the ricin and started an investigation, the indictment alleges he took an affirmative step to conceal the fact that a crime had been committed. The consequences of this action could have been disastrous."

Tholen will be issued a summons to appear in federal court in Salt Lake City, where he faces up to three years in prison and a fine of up to $250,000 if he is convicted of the charge.

Tholen is the cousin of Roger Bergendorff, who apparently was poisoned by ricin and suffered respiratory ailments. He regained consciousness March 12 after about a month in a Las Vegas hospital.

A brother, Erich Bergendorff, has said it's not clear if Roger Bergendorff made the ricin or watched someone else make the powder.

Tholen was collecting Bergendorff's belongings from the motel room on Feb. 28 when he gave a motel manager a plastic bag containing several vials of what turned out to be ricin powder.

Ricin can be deadly if ingested, inhaled or injected into the body. Authorities said that two-tenths of a milligram is enough to kill a person. It has been used in some cancer research, but it has also been used in assassinations and turned up in the homes of suspected terrorists.