After the acquisition this week of East Africa's biggest media outfit by a politically well connected billionaire businessman, questions are being asked about the future of independent journalism in the region.

Every day millions of people in Kenya, Tanzania, Uganda and Rwanda turn to one of the dozens of newspapers, TV and radio stations or digital outlets owned by the Nation Media Group (NMG) for reliable news.

In countries where journalists have come under pressure from the authorities, titles such as Kenya's Daily Nation, Tanzania's Mwananchi or Uganda's Daily Monitor have become the standard-bearers for trusted information.

But NMG now has a new majority shareholder.

Rostam Aziz, who was named Tanzania's first dollar billionaire by Forbes in 2013, announced this week that his company, Taarifa Ltd, had bought a controlling stake in the group – amounting to 54% of the business.