London, Nov 24 (IANS) One of Britain's most senior former civil servants Tuesday opened an inquiry into the circumstances surrounding Britain's 2003 invasion of Iraq, vowing to 'get to the heart of what happened' before and during the war.

Sir John Chilcot is chairman of the much-awaited inquiry, whose inquisitors include Indian-origin member of the House of Lords, Baroness Usha Parashar.

Parashar, the inaugural chairman of Britain's Judicial Appointments Commission and a cross-bench member of the upper house of parliament, will sit alongside Sir Lawrence Freedman, Sir Martin Gilberta and Sir Roderic Lyne as the sole inquisitors during the hearings.

The five-strong panel has already held meetings with the families of servicemen killed in Iraq, and with Iraq veterans. It will be the first such inquiry to be streamed live over the internet to bring it to the widest possible audience.

The inquiry, which is being held at the Queen Elizabeth II Conference Centre in London, is expected to hear at least six months of evidence before Chilcot publishes his report at the end of 2010 or early in 2011.

Former prime minister Tony Blair, who took Britain to the Iraq war in March 2003 in the face of massive popular protests, will be among the scores of witnesses who will give evidence.

One of the key questions the inquiry is expected to answer is whether Blair misled parliament over the threat posed by the Iraqi dictator Saddam Hussein, who was said at the time to have weapons of mass destruction which could be deployed at 45 minutes' notice.

The inquiry was set up by Prime Minister Gordon Brown in response to overwhelming public demand for an independent investigation into the reasons for going to war.

Although most of the hearing would be held in public, some witnesses would be heard in private where matters of national security were being discussed.