Athabasca County in northern Alberta is under federal investigation after municipal road crews allegedly disturbed habitat in a nature preserve.

The county office was closed Friday as investigators with the Environment and Climate Change Canada's wildlife enforcement branch executed a search warrant inside the building, the county said in a statement posted to its official Facebook page.

The county said the wildlife enforcement branch was investigating a complaint in relation to a road construction project along a township road adjacent to the Meanook National Wildlife Area, a federal wildlife refuge 140 kilometres north of Edmonton.

"The road construction was part of ongoing improvements to municipal roads to upgrade the road base, improve drainage to mitigate historical road flooding and contouring to improve sight lines and overall safety for the travelling public," reads a statement from the county.

"Athabasca County is alleged to have impacted lands that are part of this wildlife area."

Athabasca County said it continues to cooperate with the investigation but said no further comment will be provided, citing legal concerns.

The Meanook National Wildlife Area is a protected pocket of land that straddles boreal forest and aspen parkland. The 530-acre preserve is 17 km southwest of Athabasca.

The preserve is home to a variety of boreal songbird species and large mammals such as moose, coyote, deer and black bear.

The wildlife area is protected under federal law, and all activities which could interfere with the conservation of wildlife in the area are prohibited.

CBC News is awaiting comment from a spokesperson with Environment and Climate Change Canada.