Robert Mugabe’s son-in-law is being investigated by a special anti-corruption unit in President Emmerson Mnangagwa’s office, a newspaper reported Monday.

Simba Chikore, who is married to Mugabe’s daughter Bona, is allegedly under investigation over his role in negotiating the purchase of four second-hand Boeing 777 aircraft from Malaysia Airlines, said the private News Day.

"He (Chikore) is being investigated for his role in the deal, but it seems the whole issue could suck in Mugabe himself or better still, his wife (former First Lady Grace)," an unnamed source close to the investigation told the paper.

The procurement of the planes for a  new airline - Zimbabwe Airways - was "an intricate web that we are trying to understand," the source added.

The first of the planes landed in Zimbabwe in April, but it was flown back to Malaysia a month later for "repairs" without flying a single commercial flight, according to New Day.

There was speculation that the former first family would directly benefit from the operations of Zimbabwe Airways, though this has been denied.

In April ministers from Mnangagwa’s government insisted Chikore had no shares in the new planes, and had only been brought in to help with negotiations for their purchase, according to a report in the state-run Chronicle.