The presidential candidate of the Maoists, who is set to become first president of Nepal, had trained the former rebels on how to make explosives during the decade-long armed struggle against monarchy.
"I taught them skills to make powerful bombs, which were used during the armed struggle," Ramraja Prasad Singh told reporters after he was named as presidential candidate of the Maoists.
Singh, who did his Master's degree (Law) from Delhi University, was arrested in 1985 for throwing a small bomb at Parliament as part of an anti-royal protest.
"I'm very happy that the Maoists have supported my candidacy for president," Singh, 74, said.
Political analysts said Singh is likely to win the poll as he is also backed by three Madhesi parties.
About the relationship with India, Singh said he wanted to have closer ties with New Delhi.
"As Nepal is a landlocked country, we should establish closer ties with India," he said.
The Maoists have 226 seats in the constituent assembly and with the support of Madhesi parties, which have 86 seats, Singh is likely to get at least 314 votes against the magic number of 298 required to win the election in the constituent assembly.
Maoists, who ended their decade-long armed struggle for the abolition of monarchy in 2006 and joined the political mainstream, emerged as the single largest party after the April 10 elections and are demanding the leadership of the new government.