Islamic finance products account for about 2 per cent of the global financial services market, but with Muslims accounting for almost a quarter of the world's population, bankers expect the market to show double-digit growth for at least the next decade.
Deloitte's move is also a sign of a widening of the Islamic market. The UK government is considering raising funds in Islamic bonds and there is a growing market for Islamic retail financial products.
The Big Four groups - Deloitte, PwC, KPMG and Ernst & Young - all have Islamic teams. But, apart from Deloitte, none has a scholar, who is required to sign off that products are fully Shariah-compliant.
"We would hope by this to create a gap big enough to make it difficult [for the others] to compete," said Maghsoud Einollahi, head of De-loitte's Islamic finance team.
Scholars with the necessary training, financial expertise and - crucially - credibility, are in great demand but short supply.
The top five scholars in the field have more than 25 appointments each. Sheikh Nizam Yaqubi holds appointments on 55 Shariah boards, according to data from the Islamic Finance Information Service.
Deloitte has appointed Mufti Hassan Kaleem, a pupil of Sheikh Mohammed Taqi Usmani, who is eighth in the top-10 list by number of Shariah appointments.
Mr Kaleem will work in a consultative capacity for Deloitte. He also works for Al Baraka Bank in Pakistan, a big Islamic bank.
"I was looking for different work with different exposure," said Mr Kaleem. "Here, I will be having experience of work from tax problems, there will be structured finance problems, maybe government and institutional issues too."
But staff at other Big Four groups played down the need for a scholar.
"We have good relationships with a number of scholars and a sound understanding of major shariah issues," said Ken Eglinton, a director specialising in Islamic Financial Services at Ernst & Young, which advises on commercial and financial issues but does not give an opinion on the Shariah authenticity.
"There are variances of opinion among the scholars and accordingly the selection of scholars is particular to every organisation, sometimes based on regional factors," he added.
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