A third person has left Alberta's Energy and Utilities Board in the wake of a spying scandal.

Board chairman William Tilleman said Monday that he had accepted Al Palmer's resignation Sunday as the board's executive manager of corporate services, a position that included responsibility for security.

The board has been criticized for hiring private investigators to spy on landowners opposed to a power line between Edmonton and Calgary.

A privacy commissioner ruled the board broke the law and a government report condemned the actions.

"As I have previously stated, if future public hearings require security, the EUB will request the use of sheriffs through the Alberta solicitor general's department," Tilleman said in a press release.

"If the level of risk dictates, the police service of the jurisdiction will be consulted."

Last month, the board's security unit was disbanded and its two employees let go. The board also announced it was scrapping the current application for the transmission line and the process would have to start over.

Tilleman said Monday that he accepted Palmer's resignation as a direct result of the security issues.

The changes are being made to reassure Albertans about the role of the board, he said.