Presenting the findings in Kabul on Thursday, the NDS head, Masoom Stanekzai said the chef travelled six times to Quetta and Chaman in Balochistan to receive instructions from Taliban Quetta Shura leaders to specifically target the UAE Ambassador in Afghanistan.
Mr Stanekzai, who briefed President Ashraf Ghani two days ago, said the chef's co-workers smuggled in the explosives - a mix of RDX and TNT - in bread baskets. The explosives were placed in a sofa and detonated by remote control, he added.
Afghanistan and the UAE have demanded Pakistan hand over three plotters. The UAE delegation was in Kandahar to discuss developmental projects.
Kandahar's notorious anti-Taliban police chief, General Abdul Raziq left the room moments before the blast. The Taliban, at the time, denied responsibility saying it was a "result of local rivalry."
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.