BEIRUT (Reuters) - Iran's planned execution of billionaire Babak Zanjani for corruption will mask the identity of senior officials who supported him, say the president and two lawmakers independently assessing a case that has fuelled public cynicism about political graft.

Hundreds of Iranians have taken to social media to vent their frustration about the opaque nature and outcome of the judicial proceedings against the businessman, who says he was backed by powerful officials during the term of hardline former President Mahmoud Ahmadinejad.