A territorial dispute in an industrial part of Melbourne's west is believed to have prompted a concrete and quarrying company to fence off part of a major bike trail, forcing cyclists to detour along busy suburban roads.

The Barro Group, a long-standing family business with a string of construction interests across Melbourne and interstate, has erected metal fencing and concrete barricades across the Federation Trail in Hoppers Crossing, where the trail backs onto one of its many properties.

A family has closed off a bike path next to their property in Werribee because they say it is on their land.

VicRoads has put temporary detour signs in place along local roads but could not explain on Thursday why the path had suddenly been blocked off, or state whether the barriers would be removed.

A section of trail running alongside Skeleton Creek, north of Old Geelong Road, is now indefinitely out of bounds to the public.