The ultimate arbiters of the Islamic finance industry are not regulators, bespoke-suited bankers or the authorities, but a small, select coterie of ascetically garbed scholars versed in Koranic verses and arcane areas of jurisprudence.

This was made abundantly clear last year, when Sheikh Taqi Usmani, a leading scholar of sharia-compliant finance, shocked the industry by declaring many Islamic bonds, or sukuk, had gone too far in mimicking conventional debt.