For at least 10 years David Kay, head of the Iraq Survey Group, has staked his professional and business reputation on the case that Iraq was a serious threat.
He was a frequent pundit on US television shows, making the case for regime change in blunt language. He called the attempt by Kofi Annan, the UN Secretary General, to broker an effective inspections process in 1998 "worse than useless"; claimed in 2002 that Iraq was pursuing its weapons of mass destruction in order to bring about the elimination of the state of Israel; and said before entering Iraq that the Coalition would find not just a "smoking gun", but a "smoking arsenal".
Until October last year, Mr Kay was the vice-president of a major San Diego-based defence contractor, Science Applications International Corporation (SAIC), co-ordinating its homeland security and counter-terrorism initiatives. It was while he held this role that he claimed that Iraq could launch terrorist attacks on the US mainland.
SAIC was in the headlines earlier this year when it was revealed that the US government had given it a contract three years ago to produce mobile biological vans for training purposes. Until February SAIC's corporate vice-president was Christopher Ryan Henry, now a senior policy official at the Pentagon.
SAIC's spokesman acknowledged earlier this year that the company is deeply involved in the current war in Iraq, including its role in leading a $650m contract for services and support for the US army. Among other activities, the company runs the US-funded radio station in Umm Qasr, "Voice of the New Iraq", and helps to provide senior advisers to the US occupation authorities in Baghdad. It is not known if Mr Kay retains financial interests in SAIC.