Per NFL.com:

The downfall of Arizona State linebacker Vontaze Burfict added another chapter to its story Wednesday -- just one day before the NFL draft begins -- as NFL Network contributor and Fox Sports insider Jay Glazer reported that NFL teams were informed this week that Burfict has failed a drug test.

Teams were also told that Virginia Tech cornerback JayRon Hosley failed a drug test, according to Glazer.

NFL.com reporter Ian Rapoport confirmed, via a source, that Hosley failed his test at the NFL Scouting Combine.

Burfict has seen his draft stock plummet after a disappointing showing during the scouting combine, which followed a disastrous junior season at ASU when his weight ballooned as high as 259 pounds, and his total tackles dropped from 90 in 2010 to 69 in 2011.

Burfict did not receive an invite to work out with any NFL team during the draft evaluation process, and could possibly not be drafted at all this weekend.

Hosley wrote a letter to teams apologizing for his failed drug test, according to Glazer.