The trial kicks off at the Harare Magistrates Courts today.
The Nyanga South legislator allegedly awarded a contract to Megawatt Company without going to tender and directed NetOne to pay $4 million for the service, and $1 million for consultancy.
Mandiwanzira is also alleged to have seconded Tawanda Chinembiri to the Postal and Telecommunications Regulatory Authority board without following due process, which prejudiced the telecommunications regulator of $35 000 from allowances drawn by Chinembiri.
"The Zimbabwe Union of Journalists is following with keen interest the legal challenges facing journalist and publisher, Supa Mandiwanzira," Zimbabwe Union of Journalists secretary-general Foster Dongozi said.
Mandiwanzira is a former journalist who worked for Zimpapers' Manica Post and The Herald before joining State broadcaster, ZBC, as a business reporter and main news anchor.
He owns a multimedia company, AB Communications which runs national radio station, ZiFM Stereo; metro radio stations Hevoi FM in Masvingo, 98.4 FM in Gweru, production house Mighty Movies and Business Times, a business and financial newspaper.