Liability of tax against fake invoice

i have purchased goods in January 2019, but after 10 month the department issued me a letter that you hve purchased goods form no existing company and the said invoice is fake. the tax involved in the said fake invoice is to be paid.

now i am ready to be paid the said tax by reversing the ITC availed by us. but the dept is saying that you have to pay the said tax in cash alongwith interest and penalty.

shall i have to pay in cash alongwith interest and penalty or i have rightly reversed the said tax.

kindly state the above with exact section or rule.


thanks