Cheque Bounce But Party Died Who's Issued Cheque what to do now

My father died 2 years back but one party filed cheque bounce case against us stating that your father has taken money 1 lac long back but not paid. We were not aware of it. Last time he's sent notice but we family members were out of sation. Now summon has come from court police are telling there is arrest warrant. Kindly guide How to face this as my father died long back and complaint against legal heirs. One more thing party is teling that your mother has signed in cheque as security . But it is single account.