HALIFAX -- The RCMP in Nova Scotia have charged a 42-year-old man with uttering threats and possessing a weapon for a dangerous purpose in their investigation into a hazardous chemicals discovery in Halifax.

Christopher Burton Phillips was being brought back to Nova Scotia today from Ottawa, where he was arrested at a hotel .

Police allege in a sworn information at a Halifax provincial court that Phillips threatened a police officer and possessed a chemical called osmium tetroxide.

The document alleges the offences took place between Boxing Day and Wednesday in Cole Harbour, a suburb of Halifax.

An investigation into the discovery of hazardous chemicals at two Halifax-area homes prompted separate evacuations earlier this week.

Cpl. Greg Church says two chemists from Health Canada are helping with the investigation and an evacuation that was ordered around a cottage where hazardous chemicals were found is expected to remain in effect overnight.

"We have here of course a situation with several unknowns," Church said Thursday. "We do have two very serious criminal charges that have been laid against the individual."

He said there is no reason to believe that the areas that have been evacuated have been contaminated.