Former Eskom acting CEO Matshela Koko and EFF deputy president Floyd Shivambu have not been playing happy families on Twitter when it comes to the VBS Mutual Bank scandal.Koko took to Twitter on Thursday night to seemingly give the EFF a dose of its own medicine, by asking people to decide whether Shivambu should be linked to his younger brother Brian's alleged criminal activities.Brian Shivambu, owner of Sgameka projects, allegedly received R16m from the collapsed VBS Mutual Bank, according to a report titled "The Great Bank Heist". The damning forensic report by advocate Terry Motau and law firm Werksmans Attorneys, was published by the South African Reserve Bank (SARB) this week.Brian Shivambu has denied that he received any money.Daily Maverick reported that Floyd Shivambu himself received roughly R10m through Brian Shivambu's company.Koko tweeted: "There is a concept called "Ubaba Ka Duduzane". It was created by the @EFFSouthAfrica in parliament. It was an attempt by EFF to link Former Pres Zuma to the alleged corrupt activities of his son, Duduzane. RT if you think the concept of "Ubuti ka Brian Shivambu" makes sense here."The tweet was retweeted almost 700 times by Friday evening.EFF leader Julius Malema and other EFF MPs had often referred to former president Jacob Zuma in Parliament as Duduzane's father.Duduzane faces charges of corruption, alternatively conspiracy to commit corruption, relating to an alleged R600m offer made to former deputy finance minister Mcebisi Jonas in 2015 by Ajay Gupta, in Zuma's presence.He previously denied wrongdoing.Firing back at Koko, Floyd Shivambu responded on Twitter: "Now I understand why you were pushed over with bare minimum force to fall on your sword. How about uBaba ka Koketso. Koketso being the daughter who "without your knowledge" got R1 billion tender from ESKOM when you were an Executive there."Fin24 previously reported that Koko had faced a disciplinary hearing over allegedly not declaring a conflict of interest while his stepdaughter Koketso Choma was a director at Impulse International, a firm which benefited from about R1bn worth of contracts awarded by Eskom over 11 months.He was acquitted in that disciplinary hearing related to nepotism, but was again suspended in January this year after refusing to resign as he had been requested to do.At his latest disciplinary hearing the Eskom executive had faced four charges, including misleading Parliament about the McKinsey/Trillian payment, leaking confidential Eskom information to a Gupta associate and accepting flights to Dubai from a Gupta ally, according to Fin24.The hearing ended after it emerged during a sitting that he submitted his resignation without admitting to any guilt.Koko replied to Shivambu on Friday by tweeting: "I have welcomed that "uBaba ka Koketso" be put on the table too. Once it's on the table and is dealt with, we then go back to deal with the question I posted."