The third wife of Zulu King Goodwill Zwelithini, who died earlier this month, is expected to pick the late monarch's successor, South African media report, citing royal sources.

Queen Mantfombi MaDlamini, who has been named the interim leader of the Zulu pending the installation of a new king, is expected to appoint the king from among her sons, state broadcaster SABC reports.

The queen was named as the interim successor in the late king's will, news channel eNCA reports.

Senior members of the Zulu royal family are due to meet on Wednesday to discuss the succession of the king, after an initial meeting on Saturday.

The family will give further updates after Wednesday's meeting.

Queen Mantfombi, a sister of the current King Mswati of eSwatini (formerly known as Swaziland), is one of six wives of the late King Zwelithini.

The monarch, who was buried on Thursday, is survived by six wives and at least 30 children, including 16 sons.