A terror suspect arrested just yards from Downing Street with a rucksack full of knives took part in a controversial aid convoy to Gaza organized by the Road to Hope charity, it has emerged.

Khalid Mohammed Omar Ali, 27, was one of seven Britons on board a ship that was trying to deliver humanitarian aid to Palestinians during the Israeli blockade in 2010.

Fellow aid workers described him as a "quiet and peaceful man" who was always smiling and was driven to help others.

In a video that emerged from the convoy, Mr Ali can be seen sitting in the front of a van with a Palestinian banner tied around his head.

Speaking excitedly about his impending trip he says: "We are all getting together now, alhamdulillah, the vans are all done, energy is here, the sunshine is here, alhamdulillah [praise god]... "You are going to see in action - the youth - doing our thing, all day long. We did it in Tottenham, we are going to do it in Gaza; taking it to another level. One love."

But his experiences delivering aid to war torn areas may have left him disturbed and possibly suffering from some form of post-traumatic stress disorder, one former associate said.