A number of Renaissance Financial Holdings Limited shareholders have written to the National Social Security Authority to say the bank's acquisition was a legal nullity.
RFHL lawyer Mr Vote Muza of Muza and Nyapadi on June 22 wrote to NSSA general manager Mr James Matiza advising him of the deal to acquire RMB.
The letter was copied to Econet chief executive Mr Douglas Mboweni, RBZ Governor Dr Gideon Gono, Finance Minister Tendai Biti, Labour and Social Services Minister Paurina Mpariwa, Youth Development, Indigenisation and Empowerment Minister Saviour Kasukuwere and NSSA board members.
The former board is said to have completed the bank's sale when it had already been fired by shareholders with a 77 percent stake in the holding company.
This prompted RFHL founder Mr Patterson Timba to approach the High Court seeking to block the disposal of the bank to NSSA.
But he later withdrew the action to file a proper legal claim.
After the withdrawal, the board led by Professor Christopher Chetsanga issued Press statements suggesting that the legal challenge by Mr Timba against the disposal of the bank had failed.
NSSA has also issued a statement to say Mr Timba did not seek any specific relief against the pension fund in the case he withdrew.
"The court application had no material bearing on NSSA's investment in RMB," read part of the statement. "Its withdrawal means that as far as NSSA is aware, there is no legal challenge pending before the courts related to NSSA's involvement in RMB."
But, in his letter, Mr Muza said the board led by Prof Chetsanga had no right to represent RHFL "in your agreement with the curator and the other parties to it".
"In fact, you connived with a small group of imposters, who had been stripped of their powers, and who, through an act of desperation, attempted to railroad an illegal transaction to please their handlers at the RBZ."
Mr Muza said that, assuming that Prof Chetsanga and his other former co-directors, Mr Collin Kuhuni and Mrs Maitirwa Monica Mukonoweshuro, were validly in office as directors, "NSSA's agreement with the curator becomes invalid on another score".
This, according to the lawyer, was the fact that RMB, being a subsidiary of RFHL, had to be disposed of in terms of RFHL's Articles of Association.
"On the simple basis that there was no shareholder approval to your deal with the curator and other parties, your purported purchase of shares in Renaissance Merchant Bank is void."