The Government's star witness in the Martha Stewart trial, Douglas Faneuil, finished his direct testimony and faced cross-examination today.

Faneuil originally supported Stewart and Bacanovic's version, but struck a deal with the government in June 2002 to plead guilty to a misdemeanor and cooperate with prosecutors. Asked Wednesday to explain why he changed his story, Faneuil said: "There came a point in time where I just couldn't continue to lie. I felt that the coverup was part of my daily existence, and I just couldn't take it anymore."

As cross-examination began, Faneuil admitted he has used cocaine, marijuana and the party drugs Ecstasy and ketamine, sometimes called Special K. But he described the cocaine and ketamine uses as extremely limited, and said he had never been under the influence of any drugs during the workday at Merrill Lynch.

He also acknowledged that Bacanovic never "explicitly" directed him to lie.

Apparently, Faneuil smoked dope after signing his cooperation agreement with the Government. His agreement has a clause that says he can't break any laws. But the jury won't get to hear about it:

A routine clause in Faneuil's 2002 cooperation agreement requires him not to break the law. Stewart's attorney, Robert Morvillo, claims Faneuil broke that clause when he smoked marijuana on an April 2003 trip to Jamaica, and said the government should have "torn up" its agreement with Faneuil. But the judge did not allow defense lawyers to ask Faneuil about the trip, saying such a line of questioning amounted to "an attack on the motive of the government in presenting this case."

Faneuil faces more cross examination tomorrow.