The prosecution booked the case after the man's wife was found dead hanging in Chathirapatti in Dindigul district in April 2003 and charged that the trio had harassed her for dowry.
Allowing their appeal, Justice Aruna Jagadeesan held that there was no material evidence to prove that the woman had died due to dowry harassment.
However, there were evidences to prove that she was unhappy as the marriage was forced upon her, the judge said.
The Judge said the case lacked essential requirement that the woman was subjected to cruelty or harassment causing her to commit suicide and allowed their appeal against the lower court order.