The Twitter account directly related to the TV production of the Oscar Pistorius trial TV channel is @oscartrial199 - without the "tv" or underscore symbol.
The "199" in all the names derive from channel 199 - the channel number on DStv on which the channel is being run which has been providing live court room coverage, insights and analysis om the sensational Oscar Pistorius murder trial.
It's not clear why the Oscar Pistorius trial TV channel would consider their @oscartrial199 Twitter name as the only "official" Oscar Pistorius trial Twitter name - it is possible for anyone to create and use any untaken Twitter name on the social media network.
What has however been happening is that @oscartrial_199 has been copying, tweeting and using all of the @oscartrial199 content, while @oscartrialtv199 has been tweeting about the Oscar Pistorius court case as well.
The Oscar Pistorius trial TV channel has now been asking people to not follow the "fake Oscar trial Twitter account" and that it is being "reported".
UPDATE Friday 11 April 2014: 15:45: The Oscar Pistorius trial TV channel run by Combined Artistic Productions tells TV with Thinus in response to this morning's media enquiry that @oscartrial_199 has been reported to Twitter, and that "a notification has meanwhile been added to the fake account indicating it is a parody account and not affiliated to the official channel".
[Basically what is means is that @oscartrial_199 has been shut down now, and that @oscartrialtv199 made clear that it is a parody stream of messages.]