He is due to head off on another Kangaroos tour this time as coach for the Four Nations tournament in England later this month but it was Mal Meninga's recent trip closer to home that has uncovered family secrets dating back more than a century.

Meninga is the subject of SBS's acclaimed documentary series 'Who Do You Think You Are' due to air on Tuesday night and travels back to the South Sea Island of Tanna in the Vanuatu island group for the first time to meet ancestors and trace his family's journey to Australia.

One of the true icons of rugby league for what he achieved playing for Canberra, Queensland and Australia and his incredible coaching record with the Maroons, Meninga is the eldest of four sons to Norman Meninga and Leona Elliott but was unclear of his lineage prior to that.

Younger brother Geoff sets Meninga on his path to Tanna where there remains 'Meringa' people, the family name taking on a number of different forms as it was spelt phonetically by Australians who were bringing South Sea Islander people to work on cane farms in Queensland.

'Blackbirding' saw tens of thousands of young men from South Sea Island nations brought to Queensland to work as cheap labour but very few ever returned home at the end of their three-year 'contract'.

"The South Sea Island heritage to me is who I am. I was brought up in an Australian-South Sea Islander family and it's a difficult story to tell, none of the elders used to talk about it too much," Meninga says of the practice of blackbirding.

"My generation kept asking questions but we were kept being told not to worry about the past, worry about the future; 'This is the Australian way'.

"I think about it in a sad way because it's loss of family. The people that were blackbirded or coerced onto the boats never set foot back in their home community, their home island.

"I couldn't sleep at night, dreaming and thinking about where they are. I'd have to do something about it."

When he arrives at the village of Lowital Meninga is welcomed as a long, lost family member and connects immediately to the people and the land.

He learns of the extraordinary way in which his great grandfather Edward Meninga sought passage to Australia in 1889 and how, when South Sea Islander people were being rounded up to be returned home as part of the White Australia Policy of 1901, found a way to stay in Queensland and start a family of his own.

"I feel very fortunate for the decision he made and the courage he showed. I can't thank him enough to be honest with you, I think it's fantastic," Meninga says.

"My feeling is that I've actually found him, as opposed to losing him.

"I'm forever grateful for the choices he made way back in the 1890s."

Who Do You Think You Are featuring Mal Meninga is on SBS on Tuesday night at 7.30pm.