Judge Krishna also slapped a fine of Rs 6,000 on the man yesterday.
The prosecution case was that the man had kidnapped the 16-year-old girl with the help of his friend on March 28, 2011, taken her to Chennai, forcefully married her and then sexually assaulted her.
Two days later, he brought her back to Chidambaram and reportedly threatened her with dire consequences if she revealed anything. The girl, however, complained to her parents following which he was arrested.
The man's friend was, however, acquitted as the prosecution failed to prove its case, sources said.
