His move on Friday came after a high-ranking delegation of the ruling party African National Congress (ANC), which comprises Minister of Defence and Military Veterans Nosiviwe Mapisa-Nqakula and ANC Secretary General Ace Magashule, flew to Harare, Zimbabwe in a state-owned jet at taxpayers' expense, reports Xinhua news agency.
"In the interest of good governance and the prudent and ethical use of state assets," Ramaphosa has directed Mapisa-Nqakula to submit a detailed report within 48 hours on the circumstances that led to the minister sharing the flight to Harare with the delegation, the Presidency said in a statement.
Earlier on Friday, the opposition Democratic Alliance (DA) called on Ramaphosa to make an urgent public statement on the matter.
The trip is "a flagrant blurring of state and party lines and abuse of state machinery", amounting to theft from the people by the ANC, said the DA.
Ramaphosa said in the statement that he noted the public discussion that has been generated around the flight to Harare taken by Mapisa-Nqakula and other senior officials.
Mapisa-Nqakula allegedly had the permission of Transport Minister Fikile Mbalula to travel to Zimbabwe to meet her counterpart to discuss defence-related matters in the region following a recent Southern African Development Community summit.