Entries related to bribe given to gov. empl.

Dear sir/madam,

A company has paid some amount to gov. empl. for getting a contract, you can say bribe. Obviously, they have not issued any bill to them.  They have paid to some other gov. authorities also like for processing income tax refund, without any bill.  How to pass entry for these types? If these amount has to be included or adjusted then how the same should be done?

Thanks in advance,