Government spokesman Mobhare Matinyi said the allegations were false
The new group, which will also include the United Nations and the Organisation for Economic Cooperation and Development (OECD), will especially focus on building effective tax systems in developing countries and avoid tax base erosion, the partners said.
The decision by the organisations to formally cooperate predates the release of the so-called Panama Papers earlier this month, which highlighted the widespread use of tax haven countries by wealthy individuals to avoid taxes.
But an IMF official said the groups welcomed the heightened attention on tax issues that the controversy has stoked.