Ref. No. 961/41-105 B
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
If you know a person whose whole or major source of income is from haram, then it is not permissible to accept gifts from him. But if you have no knowledge about his income whether being haram or halal, then you can accept gifts from him and you are not obliged to check the source of his income.
Doing a job in a non-Muslim country is allowed. Government’s income maybe Halal and Haram for government itself, but for an employee whatever he receives from the government is his wage paid in exchange for his work.
As far as the Interest money is concerned it is Haram whether it is received from bank or other sources, whatsoever.
And Allah knows best
Darul Uloom Waqf Deoband