The short-term loan provider, which puts 4,212 per cent interest on its lendings, have this week agreed a shirt sponsorship deal with the Magpies which will start next season.
Under Sharia Law, Muslims are not allowed to benefit from lending or receiving money, meaning interest is banned on such things as current accounts and loans from Islamic banks.
And Shaykh Ibrahim Mogra, assistant general secretary of the Muslim Council of Britain, has now insisted those who follow Islam should take no part in promoting the company.
"There are two aspects to this. We have the rulings of the religious law and we have the individual's choice and decision on how they want to follow or not follow that rule," he told the Belfast Telegraph.
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"The idea is to protect the vulnerable and the needy from exploitation by the rich and powerful. When they are lending and are charging large amounts of interest, it means the poor will have short-term benefit from the loan but long-term difficulty in paying it back because the rate of interest is not something they can keep up with.
"The Islamic system is based on a non-interest-based system of transaction."
Of the current Newcastle squad, Demba Ba, Papiss Cisse, Cheikh Tiote and Hatem Ben Arfa are all practising Muslims.