Gov. Mark Dayton on Wednesday said state regulatory officials will investigate a pollution-control employee who sent at least two e-mails regarding the proposed Sandpiper oil pipeline that the governor called unprofessional.

The Minnesota Pollution Control Agency (MPCA) is looking into actions by Scott Lucas, a pollution-control employee in its Brainerd office, who made seemingly critical statements in e-mails on the proposed crude-oil pipeline.

The Sandpiper is a $2.6 billion project that would span 600 miles, transporting North Dakota crude oil across remote areas in northern Minnesota to a terminal in Clearbrook, and then to Superior, Wis.

Enbridge, the company behind the project, had hoped to start work on the project this year, but the Minnesota Court of Appeals in September ruled that a full environmental-impact statement must be conducted, delaying the approval process.

In one e-mail, Lucas sent a message including a link to an environmental report regarding another pipeline, saying it “could be a very useful tool for us to use when making our case against Sandpiper in this area of the state.” The e-mails were first reported by the Pioneer Press.

“Somebody in that position who’s playing an advocacy role with advocate organizations has really crossed the line of what their professional responsibilities are,” Dayton said Wednesday. “If they’re going to get into political advocacy, they should resign their position and run for the Legislature or go to work for one of the organizations that oppose the pipeline.”

It’s unclear whether the employee has played a prominent role during the regulatory approval process, said Dayton, who supports the project.

House Speaker Kurt Daudt, R-Crown, on Wednesday called the initial report and e-mails “concerning,” adding that they were “evidence that folks in the Dayton administration have been delaying this.”