24 March 2012
This is because of Explanation 1 to Section 37 which provides as under:
For the removal of doubts, it is hereby declared that any expenditure incurred by an assessee for any purpose which is an offence or which is prohibited by law shall not be deemed to have been incurred for the purpose of business or profession and no deduction or allowance shall be made in respect of such expenditure
Since giving a bribe is prohibited by law, it is not allowed as deduction.