MTN Nigeria says it’s being investigated by the country’s Economic and Financial Crimes Commission over a listing of shares on the stock exchange.

The Nigerian unit of MTN Group, Africa’s biggest wireless carrier, said in a statement on Saturday that it wasn’t accused of any wrongdoing and is cooperating with the investigation.

The South African company listed its shares on the Nigerian Stock Exchange on 16 May to comply with terms of a US$1.5-billion settlement in 2015 with the Nigerian Communications Commission over unregistered phone lines on its network.

Since the listing, the stock has jumped 41%, closing at ₦140/share on Friday, giving the company a market capitalization of ₦2.8-trillion (about R110-billion), second only to Dangote Cement.

The Lagos-based bourse said on 21 May that MTN’s shares weren’t available for buyers and urged the company to provide more of the stock for investors.

MTN is also in court challenging a $2-billion bill for alleged back taxes.  — Reported by Anthony Osae-Brown and Dulue Mbachu, with assistance from Emele Onu, (c) 2019 Bloomberg LP