Tax on unexplained income

Hi every one,

One of my client has doing business of real estate including plots development and sale. During the a.y 2008-09 my client has received advance for sale of plot for the value of rs.130laks, but  the department of income tax while doing assessment, treated advances receipt of Rs.130 laks as income and demanded to pay the tax thereon. Client has paid the tax amount as demanded by the assessing officer.

But now during the a.y 2011-12 he sold those plots for which advances receive earlier in the a.y . 2008-09 and shown as sales.

My doubt is Whether we have to pay the tax on those adances amount once again, or we can claim the credit for the amount of tax which has paid already

If we can claim the credit, what is the accounting treatment of taxes which we have paid against demand notice of department for the a.y 2008-09.

Its an urgent issue

Please let me know the  solution for this

Thanks in advance to all my friends