A former Calgary man faces charges of threatening two Crown prosecutors.

Benjamin Christensen, 27, is charged with extortion, uttering threats and intimidation.

Police say the prosecutors received threats in an email in March, apparently trying to have charges dropped against his associate.

"There was an email component so we had to use our cyber crime team and get some search warrants to recover some items and some further evidence," said Harve Davies with the Calgary Police Service.

"We had to deal with the Crown's office to make sure that security was looked after for their people. Our behavioural sciences unit was involved in this, so there was a lot of different moving parts in this investigation."

Christensen was arrested by Lethbridge Regional Police on Friday.

While in Calgary, Christensen acted as an agent for Occupy Calgary protesters in a legal battle with the city in 2011.

He also tried to run in the Calgary Centre byelection last year for the Progressive Canadian Party.

Christensen will be back in court Aug. 6.