US companies are among those making profits in the South Sudan conflict, an activist and expert on South Sudan has told the US Congress.

John Prendergast of the Enough Project cited Frontier Services Group, which he said signed a contract of 5.6 million US dollars to deliver military logistical support without a license from the United States.

He said greed is the main driver in the South Sudan conflict.

The expert also told congressmen that the competing factions of the SPLM hijacked the state and used its institutions and deadly force to maintain or acquire power.

Mr Prendergast said greed, despite its centrality in the conflict, is a factor that has not been addressed by international peace efforts.

Excerpts of his testimony yesterday, after a visit to South Sudan early this year, have been posted on the website of Enough Project.