Increasing complaints about clogged fuel filters have led Minnesota officials to temporarily suspend a biodiesel mandate that has been in place since October.

The suspension, which went into effect Friday, Dec. 23, will last until Jan. 13, 2006. Officials say it should give researchers enough time to determine exactly what is causing the problems.

Reports of clogged fuel filters have been on the increase in Minnesota since October, when the state issued a mandate requiring that all diesel sold in the state be a 2 percent biodiesel blend.

The St. Paul Pioneer Press reported that even the Minnesota Biodiesel Council supports the reprieve, hoping it will give suppliers and manufacturers time to test their inventories and figure out what the problem is.

While numerous theories abound, no one cause has been determined, and Gov. Tim Pawlenty said he is waiting for test results from the state Department of Commerce before taking further action.

In the meantime, anyone with problems is asked to contact the University of Minnesota Biodiesel Helpline at 1-800-929-3437 if located in Minnesota or (651) 330-0450 outside of the state.