Expired cheques need to be write off

Dear All,

I would like to get suggestion on a question that is being ran in my mind that some Bank enteries are coming since F.Y. 2010-11 to till the date. Means Cheques issued and received but not presented/reflected in Bank. They had been expired from their issuing date.

Auditor came and made the Balance sheets for the F.Y. 2010-11, 2011-12 & 2012-13 but didn't suggest or write off those cheques cause of this entries are still shown in reconciliation of Bank accounts.

Now could you please tell me when i can do write off those entries.

Is it okay to write off in the current year???