House Speaker Kurt Daudt, R-Crown, asked the legislative auditor to investigate a situation involving a pollution-control employee who made seemingly critical statements in e-mails about the Sandpiper oil pipeline that awaits regulatory approval.
The e-mails "appear highly inappropriate" and "indicate a strong desire to delay and undermine the project, rather than abide by a fair and impartial regulatory process," Daudt wrote in his letter.
Daudt is also asking Legislative Auditor Jim Nobles to investigate how the administration of Gov. Mark Dayton is handling the matter.
The legislative auditor is an independent investigative arm of the Legislature.
Dayton, who has voiced support for the Sandpiper project, has already said the e-mails in question were unprofessional.
The Minnesota Pollution Control Agency (MPCA) is looking into the actions of Scott Lucas, the pollution-control employee in its Brainerd office.
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.