Canadian police allege in court documents that an American man at the center of an investigation into hazardous chemicals threatened a police officer and possessed a dangerous chemical.

Police allege 42-year-old Christopher Burton Phillips possessed a chemical called osmium tetroxide for a dangerous purpose. An investigation into the discovery of hazardous chemicals prompted two evacuations in Halifax this week.

Ottawa police arrested Phillips at a hotel Wednesday and linked the arrest to the discovery of the chemicals in Halifax. Police say they found no hazardous materials in the Ottawa hotel.

The court documents allege the offenses took place between Dec. 26 and Jan. 21 in a Halifax suburb.

Phillips is the ex-husband of former U.S. Olympic gymnast Shannon Miller.