L Dhaballo, an executive engineer of the Manipur Public Health Engineering Department (PHED) was released at Langol area in Imphal on Thursday, Dec 10 evening, officials said on Friday, Dec 11.
However, the officials do not know if the ransom had been paid for his release or not.
According to reports, the militants, who kidnapped the engineer on Dec 3, had demanded a huge sum of money as ransom from his department.
Two other engineers of Manipur electricity department were kidnapped in Nov 2009. Officials said that Executive Engineer TH Tomalchand and Section Officer L Mangi have not been freed yet.