His attraction towards incendiary material started in his childhood -- while he was in school and keenly observed a 'chooranwalah' doing tricks, like cracker-type fire and explosion, using potash, sugar and acid, said police after questioning him for a day.
"When he was aged 12, Tunda observed 'Chooranwalah' sprinkling acid on a mixture of potash and sugar to produce fire. He developed this principle to make bombs," Joint Commissioner of Police (Special Cell) Madan Oberoi told IANS.
The 70-year-old terrorist used locally available materials like urea, nitric acid, potassium chloride, nitrobenzene and sugar to make bombs. His left hand got blown off while making a bomb in 1985 in Mumbai, after which he got the moniker of Tunda - which means one-handed man.
Police said after becoming a radicalised jehadi, Tunda started providing bomb-making training to youths. "He has been training young indoctrinated radicals to make bombs for the last 28 years," said Oberoi.
Investigators said Tunda also trained terror operatives in making improvised explosive devices (IEDs), police said.
In Mumbai, the Delhi-born, Class 7 dropout joined Jalees Ansari to form a new group Tanzeem Islah ul-Muslimeen (an armed organisation aiming to work for the Muslim community).
Investigators said in 1993 Tunda and Ansari had set off a series of bombs in Mumbai. Ansari was arrest in January 1994 and after some time he fled to Bangladesh's capital Dhaka where he started training jehadis in bomb-making.
"He has a good network in India, Nepal, Bangladesh and Pakistan. He has relations with terror organisations -- including Lashkar-e-Taiba, Jaish-e-Mohammed, Indian Mujahideen, Babbar Khalsa International (BKI) and underworld don Dawood Ibrahim," said Oberoi.
Tunda was connected with BKI chief Wadhawa Singh, who used Tunda's network in 2010 to smuggle a consignment of explosives into India.
Tunda had an excellent network of operatives through which he sent men and material into India. He has also been sending explosives and fake Indian currency to India, he said.
One of his destructive plans, made at the behest of the BKI in 20101, was foiled.
"The explosives which were assembled outside Pakistan were to be sent somewhere in Delhi or Punjab. However, the plot failed as Tunda's operatives were arrested in Bangladesh before they could execute the plan," said a police officer.
During interrogation, Tunda told police that he met don Dawood Ibrahim in Karachi several times.
"He claims that Dawood first called him for a meet in 2000. He says that the underworld don stays in a safe house in Karachi and is guarded by the ISI (Pakistan's intelligence agency). His movement is restricted and monitored by the intelligence agency," added the officer.