Former aide: Powell WMD speech 'lowest point in my life'

Programming Note: " 'Dead Wrong' -- Inside an Intelligence Meltdown" airs Sunday at 8 p.m. and 11 p.m. ET on CNN.

(CNN) -- A former top aide to Colin Powell says his involvement in the former secretary of state's presentation to the United Nations on Iraq's weapons of mass destruction was "the lowest point" in his life.

"I wish I had not been involved in it," says Col. Lawrence Wilkerson, a longtime Powell adviser who served as his chief of staff from 2002 through 2005. "I look back on it, and I still say it was the lowest point in my life."

Wilkerson is one of several insiders interviewed for the CNN Presents documentary "Dead Wrong -- Inside an Intelligence Meltdown." The program, which airs Sunday at 8 p.m. and 11 p.m. ET, pieces together the events leading up to the mistaken WMD intelligence that was presented to the public. A presidential commission that investigated the pre-war WMD intelligence found much of it to be "dead wrong."

Powell's speech, delivered on February 5, 2003, made the case for the war by presenting U.S. intelligence that purported to prove that Saddam Hussein had weapons of mass destruction. Wilkerson says the information in Powell's presentation initially came from a document he described as "sort of a Chinese menu" that was provided by the White House.