Just over a year after Bob Diamond founded Atlas Mara to build an African banking empire, problems are cropping up.

Some investors are questioning the lavish pay doled out to managers at the investment vehicle set up by the ex-Barclays chief executive. Local regulators have delayed a key Atlas Mara hire. The vehicle's publicly traded shares have nose-dived. And corporate governance experts are criticising a personal shareholding by Diamond in one of Atlas Mara's acquisition targets, which wasn't fully disclosed until months after Atlas Mara offered to buy it.