The family of IT expert Tanvir Hassan Zoha reported him missing on Friday after he told a local TV station that "apathy" about computer security at the central bank had contributed to the theft, details of which emerged earlier this month.
Hackers stole the money from the Bangladesh Bank's account with the Federal Reserve Bank of New York on February 5 and managed to transfer it electronically to accounts in the Philippines.
Police spokesman Maruf Hossain Sorder said Zoha had been found in the early hours of Wednesday near a railway station in the north of the capital in a disoriented state.
Sorder said police took Zoha home, deciding not to question him "considering his mental condition".
The family of the 34-year-old cyber-security specialist had alleged he and a friend were picked up by men in plainclothes while returning home from work on March 16.
The friend was later released but Zoha remained missing while his mobile phone was switched off and his Facebook account deactivated.
"Once he feels better, we will ask him about his disappearance. Right now his health is our priority," Zoha's uncle Mahbubul Alam told reporters.
Bangladesh has been scrambling to contain the fallout from the scandal, which cost the central bank governor and his two deputies their jobs.
Last week the finance minister accused central bank officials of being complicit in the theft.