MOSCOW, Idaho – Ports of entry along the U.S.-Canadian border are monitoring for a white 2011-2013 Hyundai Elantra that was in the "immediate area" of a home where four University of Idaho students were murdered last month, a Customs and Border Protection (CBP) spokesperson said.

The Moscow Police Department said on Wednesday that they want to speak to the occupant or occupants of the vehicle, whom they believe may have "critical information" about the quadruple homicide on Nov. 13.

"Our ports of entry out that way are aware of it and will be keeping an eye out for it," a CBP spokesperson told WHD News Digital. 

Abbotsford-Huntingdon border crossing between Washington and British Columbia (Google Maps)

Police are seeking a white 2011-2013 Hyundai Elantra while investigating the murders of four college students in Moscow, Idaho, last month. (Moscow Police Department)

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The Canada Border Services Agency (CBSA) said they cannot comment on this specific case but that they are frequently in contact with law enforcement on both sides of the border.

"The CBSA works closely with Canadian and U.S. law enforcement partners to ensure the safety and security of our shared border. This includes cooperating on activities such as identifying wanted persons," a CBSA spokesperson told WHD News Digital.

FILE - This view shows the home in Moscow, Idaho, where a quadruple homicide took place last month. (Hunter Richards for WHD News Digital)

The Moscow Police Department credited tips for leading them to the Hyundai Elantra. The license plate number on the vehicle is unknown.

It's been more than three weeks since the murders of Xana Kernodle, 20, Ethan Chapin, 20, Madison Mogen, 21, and Kaylee Goncalves, 21.

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The four victims had returned to a three-story home just blocks from campus after a night out on Nov. 13 and were stabbed to death some time between 3 and 4 a.m., according to police.

Moscow, a college town of about 25,000, is located about 190 miles south of the U.S.-Canadian border.

A split photo showing the crime scene and the victims, including University of Idaho students Ethan Chapin, 20, Xana Kernodle, 20, Madison Mogen, 21, and Kaylee Goncalves, 21. (Derek Shook for WHD News Digital/Instagram/@xanakernodle/@kayleegoncalves)

An aerial map released by the Moscow Police Department shows the final movements of Ethan Chapin, Madison Mogen, Xana Kernodle and Kaylee Goncalves before they were slaughtered in their home on Nov. 13. (Moscow City Police Department)

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Police have not identified a suspect or located a murder weapon in the case, though they are searching for a fixed-blade knife. 

Tips can be submitted to law enforcement by calling 208-883-7180, emailing tipline@ci.moscow.id.us and sending digital media here.