Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 2 years ago

If the amount is been invested in lawful business away from unlawful business e.g. alcohol, pork, usury etc, then the income from it will be lawful. Such income can not be fixed by a percentage from the capital, but it must depend on the profit if any.

Fixed amounts given by non Muslims is allowed for the Muslim to receive and utilize in lawful needs and aims.