The Democratic Alliance on Sunday welcomed news that Public Protector Busisiwe Mkhwebane will investigate the social grant saga.
"The DA... hopes that the Public Protector's investigation will shed some light on how this crisis came about," MP Bridget Masango said in a statement.
She said that the party wanted all those responsible to be "brought to account".
On Saturday, Mkhwebane announced that, on her "own initiative" she was planning to investigate the South African Social Security Agency (Sassa).
This follows a Constitutional Court ruling on Friday that the privately-owned Cash Paymaster Services must continue distributing social grants for another year, after Sassa failed to in-source the payment of social grants.