Is It Mandatory To Show Lent Amount In It Returns To Recover .

i have filed a debt on promissory note case in dec.2015 as the borrower died without repaying.as i am tax payer in that assessment year showed that i have unsecured loans more than the amount i gave, but i havn't shown that i gave amount to deceased on promissory note.but as per my income tax i am capable to lend amount to him.now i would like to know as i wasn't shown in income tax returns that amount so is it not maintainable in court or not. some body saying not maintainable,if maintainable please provide me your advise and some of exemplary cases.