Federal investigators have joined the search for missing 23-year-old Abdullah Abdullatif Alkadi, who is a full-time student at CSUN. (credit: LAPD)

LOS ANGELES (CBSLA.com/AP) — The LAPD says the FBI is assisting in the investigation of a California State University, Northridge, student from Saudi Arabia who went missing two weeks ago.

Detective Frank Flores the FBI expressed interest in the search for Abdullah Alkadi because he’s a foreign student, according to The Los Angeles Daily News.

The 23-year-old was reported missing Sept. 18 by his brother. He was last seen at home the night before by his roommates.

He is a student of electrical engineering and has been studying in the United States since 2010.

His brother says around the time of his disappearance Alkadi sold one of his cars, an Audi S-5, via Craigslist. The vehicle has a suggested retail price of roughly $52,000.

Police have since found the vehicle and said the buyer is not linked to the CSUN student’s disappearance, The Associated Press reported.

Following his disappearance, police traced Abdullah Alkadi’s cell phone to Beaumont, east of Moreno Valley and Redlands, where it was deactivated.

Ahmed Alkadi says his brother has no ties.

“We have been in misery,” Alkadi told City News Service last month. “We have tried everything. We called friends. We called relatives. We called everybody we knew and with no news. We are so worried about him.”

Flores said the department is following up on all available leads but would not offer further details on the investigation.

(TM and © Copyright 2014 CBS Local Media, a division of CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)