Alberta’s arms-length energy regulator hired a private investigator to pose as a concerned citizen and infiltrate a group of landowners opposing the construction of a massive power line, new documents show.

The provincial NDP released documents obtained under Freedom of Information legislation Thursday that also show investigators gave the Energy and Utilities Board passwords that would allow it to listen in on the landowners’ private conference calls.

NDP leader Brian Mason said it is a case of using public money to spy on Albertans.

“This goes far beyond what’s necessary to protect the integrity of the hearing,” Mason said.

“This was intelligence gathering and it was political intelligence.”

Landowner Joe Anglin called the documents “a huge vindication.”