Manitowish Waters, Wis. ? Investigators found ingredients that could be used to make the deadly poison ricin in a cabin owned by a man accused of having explosives, the Vilas County sheriff said Sunday.

Sheriff John Niebuhr said investigators found no signs the man intended to make and use ricin.

The ingredients “were not mixed, no process started, no finished product, no setup, no lab, nothing,” Niebuhr said.

Investigators also found no sign the man was linked to any terrorist group, Niebuhr said.

According to the U.S. Centers for Disease Control and Prevention, as little as 500 micrograms of ricin, roughly the amount that fits on the head of a pin, is enough to kill an adult.

The ingredients were found during a two-day search of the Manitowish Waters cabin owned by Denys Ray Hughes, Niebuhr said. The sheriff refused to identify the ingredients or reveal what else was found in the cabin, located in far northern Wisconsin.

Vilas County deputies arrested Hughes, 58, last week on suspicion of having explosives. He was turned over to federal authorities, who charged him with possessing destructive devices and a silencer. His preliminary hearing is scheduled Tuesday in U.S. District Court in Madison.

The investigation started after Hughes, an honorably discharged Army veteran, was stopped July 8 for a traffic violation in Russell County, Kan. Sheriff’s officials found glass containers, firearms, reloading supplies and books referencing bomb-making in his car and passed the information to the Bureau of Alcohol, Tobacco, Firearms and Explosives, authorities said.