RNZ reports Jacob Umaga, who is the son of Tana's brother Mike, has previously played for England at under 18 level.
The Wasps first five has been named to start for England under 20's against Wales this weekend.
The 18-year-old Umaga came on as a replacement at centre against France last weekend and recently made his senior debut at fly half for Wasps in the Anglo-Welsh Cup.
Jacob Umaga was born in England.
