An autopsy has not yet been able to determine the cause of death for Elisa Lam, a Vancouver woman whose body was found in a hotel rooftop water tank in Los Angeles.

Lam, 21, was last seen in the lobby of the Cecil Hotel on Jan. 31. A staff member, who was investigating guest complaints of low water pressure, discovered her body in a water tank on Tuesday morning.

An autopsy was completed on Thursday but the cause of death has been "deferred, pending additional tests," said Ed Winter, L.A. County assistant chief coroner.

The office is waiting for results of blood, urine and toxicology tests that are expected in six to eight weeks. Until then, the coroner won't be releasing any partial or preliminary information, he said.

"What was in her system? Were all the organs functioning right? ... Any prescriptions, was she on meds within a therapeutic level or did she take too many or was there none?" said Winter in explaining what the coroner is looking for.

Lam, who attended the University of British Columbia, had been travelling in California alone but was in daily contact with her parents when she disappeared.

During their search, L.A. police released surveillance video from the hotel elevator that showed Lam appearing agitated, pushing several buttons and peering into the hallway as if to look for someone.

Related on HuffPost:

Loading Slideshow...
  • Jan. 26, 2013 - Arrival In L.A.

    21-year-old <a href="http://www.lapdonline.org/newsroom/news_view/52943">Elisa Lam</a> of Vancouver, B.C. arrived in L.A. on Jan. 26. The University of British Columbia student was travelling by herself.

  • Jan. 28, 2013 - Hotel Check-In

    Lam checked into the Cecil Hotel in <a href="http://www.huffingtonpost.ca/2013/02/06/elisa-lam-missing-vancouver-la-disappearance_n_2632632.html">downtown Los Angeles</a> on Jan. 28. She was set to check out on Feb. 1, reported KTLA.

  • Jan. 31, 2013 - Last Seen Alive

    Lam was last seen alive in the lobby of the Cecil Hotel on Jan. 31. She had been in contact with her family daily. Her <a href="http://www.huffingtonpost.ca/2013/02/06/elisa-lam-missing-vancouver-la-disappearance_n_2632632.html">disappearance was called "suspicious"</a> by police.

  • Feb. 8, 2013 - Friend Calls Lam "Caring"

    Friends called Lam a <a href="http://www.huffingtonpost.ca/2013/02/08/elisa-lam-vancouver-student-missing-los-angeles_n_2647593.html">caring and conscientious woman</a>. She had been travelling alone in California. Police said her reason for travelling in the state was "unclear."

  • Feb. 14, 2013 - Troubling Video Released

    <a href="http://www.huffingtonpost.ca/2013/02/14/elisa-lam-missing-video-la-vancouver_n_2688168.html">LAPD released</a> a troubling video captured from the <a href="http://www.youtube.com/watch?feature=player_embedded&v=Zq4LmWiDiC0">Cecil Hotel's elevator surveillance</a> camera of Lam behaving strangely.

  • Feb. 19, 2013 - Body Found

    On Feb. 19, Lam's body was discovered by a worker in one of the <a href="http://www.huffingtonpost.ca/2013/02/19/elisa-lam-dead-missing-vancouver-body-found-la_n_2719564.html">Cecil Hotel</a>'s four water tanks on the building's roof. They were checking a complaint about low water pressure.

  • Feb. 20, 2013 - Guests Leave Hotel After Lam Found

    A man, left, leaves the Cecil Hotel with belongings as Michael and Sabina Baugh, both 27, of Plymouth, England, wait for transportation as they leave the hotel in downtown Los Angeles on Feb. 20. Early Tuesday, police discovered the body of a Canadian woman at the bottom of the historic hotel's water tank, weeks after she was reported missing. The Baughs, on a 14-day tour package, had been there eight days and had showered in and drank the water. The couple's tour operator was less than cooperative in finding them other accommodations.

  • Feb. 21, 2013 - Autopsy Complete

    An autopsy on the body was completed on Feb. 21, but the <a href="http://www.huffingtonpost.ca/2013/02/21/elisa-lam-autopsy-missing-la-die_n_2736358.html">cause of death</a> has been "deferred pending additional tests," said Ed Winter, L.A. Country assistant chief coroner.

  • Feb. 26, 2013 - Class-Action Lawsuit Filed

    Two former guests file a <a href="http://www.huffingtonpost.ca/2013/03/01/elisa-lam-case-cecil-hotel-lawsuit_n_2793453.html?1362186011">class-action lawsuit</a> against the Cecil Hotel after Elisa Lam's body was found in a water tank.

  • Jun. 20, 2013 - Cause Of Death Confirmed

    Elisa Lam died of "<a href="http://www.huffingtonpost.ca/2013/06/20/elisa-lam-death-accidental_n_3474116.html" target="_blank">accidental due to drowning, other significant conditions: bipolar disorder</a>," confirmed Los Angeles County Coroner.