The Los Angeles Coroner said via exclusive e-mail Thursday that a toxicology report may be necessary to determine conservative journalist Andrew Breitbart's cause of death.

Craig R. Harvey, chief coroner investigator and chief of operations for the Los Angeles Coroner's Office, offered new details about the office's plans for determining Breitbart's cause of death (COD) in the Thursday afternoon e-mail. Breitbart died shortly after midnight Thursday in Los Angeles at the age of 43.

The exam may take place as soon as Friday, Harvey wrote. Whether or not we have a COD at that time is another story. We may end up waiting for tox.

The word tox in his e-mail refers to a full toxicology report, often undertaken when a person dies suddenly to determine whether drugs, alcohol, poisons or other foreign substances were a factor in causing a person's death.

In a previous e-mail, Harvey confirmed Andrew Breitbart's time and place of death as being 12:19 a.m. Thursday at UCLA Medical Center in Los Angeles.

Harvey went on to offer the following short comment in his initial e-mail:

Body not yet examined. No final cause of death yet established by the Coroner, Harvey wrote.

And Joel Pollak, a spokesman for Breitbart, said in an e-mail Thursday morning that he had no further information about his death:      

Shortly after midnight Thursday, Breitbart was walking near his Brentwood, Calif., home, when an unidentified witness saw him collapse and fall, Breitbart's father-in-law Orson Bean said, according to NBC News.

The person who saw him fall then called 911, and emergency responders found him unconscious, tried to revive him, and took him to UCLA Medical Center, Bean said, according to NBC.

Someone saw Breitbart fall and called 911. Emergency crews tried to revive him and rushed him to the emergency room at UCLA Medical Center, Bean said.

Breitbart is survived by his wife and four children, and a moving family message was posted on his websiteThursday morning:

With a terrible feeling of pain and loss we announce the passing of Andrew Breitbart. Andrew passed away unexpectedly from natural causes shortly after midnight this morning in Los Angeles, the message reads. We have lost a husband, a father, a son, a brother, a dear friend, a patriot and a happy warrior. Andrew lived boldly, so that we more timid souls would dare to live freely and fully, and fight for the fragile liberty he showed us how to love.

Breitbart was the head of a self-made media empire that saw the reporter break several major stories over the past five years. From his investigations of ACORN and Media Matters to the peak of his fame, which came last year as he took the podium on national television while reporters awaited Anthony Weiner's teary resignation, Breitbart had a way of making himself and his work part of the story.

Ever since the early days of Barack Obama's run for president, Breitbart had his hands in the pot. He got Shirley Sherrod forced out of Obama's circle and was constantly working on his next big investigation.

The investigation into the official cause of Breitbart's death is ongoing.