"He (Mishra) has been released unharmed by his captors in Dalu-Gasuapara road. He is in Dalu police station," Lakador Syiem, the district police chief, told IANS.
Mishra, who is from Bihar, rang up his father informing him that he has been freed by his captors.
However, intelligence official said Mishra was released unharmed after negotiations on the ransom amount.
"We don't know yet the exact ransom that was paid to the militants by Mishra's family but a substantial amount was paid to them," the intelligence official said on the condition of anonymity.
The ASAK, which means "vanguards of Garoland", is one of nine Garo rebel groups operating in western Meghalaya, had demanded a ransom of Rs.one crore for the safe release of Mishra.
The Garo militant outfit is fighting for a separate Garoland out of Meghalaya.