A central Alberta landowners' group is calling for a criminal investigation into accusations that Alberta's Energy and Utilities Board hired private investigators to spy on them during recent hearings.

On Monday, Energy Minister Mel Knight ordered an independent review of the allegations. Alberta's information and privacy commissioner, Frank Work, as well as the Office of the Ombudsman are also investigating.

Jason Chance, a spokesman for Alberta Energy, said former Court of Queen's Bench justice Del Perras will take on the independent review and complete his investigation by September.

Joe Anglin, a spokesman for the Lavesta Area Group, said his group doesn't believe any of the investigations will be truly independent, and are demanding a fourth investigation.

"[If] we get to the point where maybe we get the RCMP involved, or some real serious judicial body that will open this up, then we might have a level of trust that might be restored."

He said the hearings should also be restarted.

Alberta's Energy and Utilities Board is considering a controversial proposal from AltaLink to build a 500-kilovolt power line between Calgary and Edmonton.

Landowners living near the proposed site of the power line are concerned about possible health effects and have complained that the board has already decided to approve it.

In April, board staff alleged they were physically threatened in three incidents at a public hearing into the project. Afterward, the board decided to accept only written submissions and close the courtroom in the central Alberta town of Rimbey.

Landowners were moved into a nearby recreation centre to watch the proceedings on TV.

In June, board spokesman Davis Sheremata admitted the energy regulator had hired "security personnel" to keep an eye on the landowners watching the hearings in the recreation centre.