Mr McLean said interest generated by the Times-Age story had been very helpful.
Tadophile Adele Pentony-Graham directed him to Maori historian Rex Hemi "who did a lot of digging" and Wairarapa archivist Gareth Winter lent a hand.
He said he was now directing his enquiries to Ngai Tahu and Canterbury Museum.
An obituary in the National Library's Papers Past described Pita te Hori as one of the "boldest defenders" of the Kaiapoi pa, north of what is now Christchurch, against Ngati Toa chieftain Te Rauparaha.
Captured, he escaped to rally a counter-attack against Ngati Toa, defeating Te Rauparaha at Queen Charlotte Sound.
He later joined a deputation of chiefs to Wellington to negotiate a truce between Te Rauparaha and the southern tribes.