Arrested from Mumbra for running a fake currency racket, Haroon Naik, 33, is among the top Indian Mujahideen (IM) operatives in the country, the state anti-terrorism squad (ATS) now claims.
The ATS suspects Naik played a crucial role in last year's July 13 triple blasts, and ranks alongside IM's top leaders Amir Raza Khan, and brothers Riyaz and Iqbal Bhatkal.
Rakesh Maria, additional director general of police and ATS chief, said, "He is an extremely important operative, who was part of the core team of Indian Mujahideen. He could be ranked third or fourth in IM's hierarchy."
Naik, who spent his early days in Kurla and Malegaon, was indoctrinated when his family shifted to Cheetah Camp in Trombay.
ATS officials say it was here that he met a radicalised Riyaz and Tariq Ismail, who indoctrinated him.
Riyaz is among the most wanted terrorists in the country and co-founded the banned terrorist group, which is said to have affiliations with Lashkar-e-Taiba (LeT), while Ismail is an absconding accused in a number of cases, including the 2006 serial train blasts in Mumbai.
After his indoctrination, Naik was sent to Pakistan in late 2000 for training at the infamous Bahawalpur academy headed by LeT's then chief of India operations Azam Cheema.
He first undertook the basic LeT courses of Daura-e-Aam and Daura-e-Khaas, and after he showed interest in fighting against the Northern Alliance and the US forces in Afghanistan, he was trained in the Bait-ur-Rizwan course, a commando training which is allegedly imparted by Pakistan army's special services group known as the Zarar Company, ATS sources said.
Naik then joined Al-Qaeda fighters in Kandahar, and first fought against the Northern Alliance and later against the US forces.
In 2004, he returned to Pakistan and then went to Saudi Arabia, which he made his base with Riyaz's help.
In 2005, Naik crossed over to Pakistan again from the Wagah border using a Nepalese passport. "We have collected the evidence to prove his transit to Pakistan," said Maria.
From then on, Naik used various names - Salauddin, Umar and Maulana - to enter and exit India using either the Bangladesh or Nepal route, and was handling IM's operations in the country, ATS sources said.