French sources say the Magpies have continually kept tabs on the £9m-rated Gabon international throughout the winter.
Toon owner Mike Ashley jetted out to France with chief scout Graham Carr to see him play for St Etienne in their 2-2 draw with Paris-Saint Germain.
The recent rib injury scare for Papiss Cisse has underlined just how thin on the ground Newcastle are when it comes to strikers, with only Shola Ameobi as an alternative in terms of a senior out-and-out forward.