China’s largest construction company has confirmed it is in talks about building South Africa’s first high-speed rail line.

China Railway Group said it had had “early stage contact” with a group of South African companies about plans to create the first high-speed link in sub-Saharan Africa.

South Africa’s Standard Bank, which is 20 per cent owned by the Industrial and Commercial Bank of China, told the Financial Times that it had signed a memorandum of understanding with China Railway to finance projects in the country.

According to the South African press, ahead of President Jacob Zuma’s visit to China, an agreement to build a $30bn high-speed line between Johannesburg and Durban could be one of the deals signed.

A high-speed rail line connecting Johannesburg and Durban could ease road congestion between the two cities, as well as reduce the reliance of the dozens of daily flights linking the economic hubs.

The only country in Africa committed to a high-speed rail line is Morocco, which has started work on a link between the port city of Tangier to Casablanca, 750km away, with a completion date of 2015.

Critics in South Africa say there are not enough people interested to justify construction of a line, and that it would have to carry freight to make it viable. They also cite more pressing transport issues, such as improving the rail transport of the country’s mining industries.

They also argue that millions of township residents face difficult journeys to work in big cities, and that resources would be better spent building South Africa’s road network and suburban public transport.

The first phase of South Africa’s only existing fast passenger line, the Gautrain project linking central Johannesburg to Pretoria and the region’s airport, opened in June and has already proved a big success. The project is due to be completed next year.