suicide by wife

Sir, I got married 11/2 years back. my wife committed suicide 33 days ago and no complaint is lodged against me .She was in sever depression due to her illness of UTI problem from next week of marriage and after six month of treatment Gyna doct advised us to take her to mental doctor and her treatment of depression was going on since last six months and all the prescription of 4 psychiatrist(private and govt hospital )are with me.Since last one month she was with her parents who took her delhi for mental treatment .when she came back from Delhi committed suicide in her parents house. Initially my wife parents supported and behaved well.Now they are asking us to return all matri expenses which is not an issue but also threatening us for complaint against us stating that they have suicide note which they didnt declare earlier(perhaps expecting more money from us). Her father along with me went to police station for information and father written that "his daughter commit suicide due to mental problem and treatment was going on" .all police formalities are been done in presence of mine and my family and body is received by us after PM.i also signed in pancnama.Now its 33 days over .Help me to find out the way out if he accused us now and what are the remedies.Can they file allegation against us .