Answer:
(Fatwa: 1888/127=D/1429)
(a) It is not lawful to give salary even to non-Muslims from the unlawful income, but it is wajib (essential) to give such money in sadqah, so you should do sadqah.
(b) It is also not permissible to pay income tax with that money, albeit it is allowable to pay income tax with interest money but you can pay income tax with the interest you have received from the government or the governmental banks.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
