Public Protector Busisiwe Mkhwebane is planning to investigate the South African Social Security Agency (Sassa), a spokesperson said on Saturday.
This follows a Constitutional Court ruling on Friday that privately-owned Cash Paymaster Services (CPS) must to continue distributing social grants for another year, after Sassa failed to insource the payment of social grants.
Mkhwebane's spokesperson Oupa Segalwe told News24 that the investigation was her "own initiative".
"Mkhwebane already wrote to the ministers and directors-general of Social Development and Finance early last week to bring to their attention her intention to investigate," Segalwe said.
"In the correspondence to Treasury, she had asked for available options for an uninterrupted pay out of grants but she has since taken note of yesterday's Constitutional Court judgment giving directives on the matter."
Segalwe said the public protector would also investigate a complaint brought by the Democratic Alliance to look into the relationship between Minister of Social Development Bathabile Dlamini and CPS.
Segalwe could not say when the investigation would be concluded.