"I don't know what prompted the President to call the minister from a conference as important as that to come home. It must be a serious matter," Nkwinti said during a media briefing in Cape Town.
Nkwinti was briefing journalists on several land reform bills out for public comment when he was asked whether he knew why Gordhan was told to return to South Africa from London where the finance minister and his team was meeting with investors.
The minister said he heard about Gordhan being called back home on the radio news as he was travelling from Pretoria to the airport and also later learnt that Zuma had joined the Gupta court case as an interested party.
In that case, being heard in the high court in Pretoria on Tuesday, Gordhan is seeking a declaratory order that he can't interfere in the decision by four of South Africa's major banks to close the accounts of companies owned by the Gupta family, who are close to Zuma. Nkwinti said he would be following the case on television.
"I don't have the detail of that at all. I'm going to follow it through today."