He said he had barred the old and new owners from the park, essentially stopping St Morris from taking boats across the land to launch because of an assumed right to do so.
"Ray brings them in to meet me and he's obviously told them it's free access across here. More than anything, I was not happy about it. So I told them: 'There is no free access, if you want to come across here you can pay.' That's the long and the short of it.
"I can't believe someone would have allowed someone to buy an island without knowing how they got there."
Mr Grimwood said access was not a problem in the past because guests were usually flown to the island by helicopter. He said he had met representatives of St Morris but never its shareholder, Wenning Han, who remains a mystery.
Former Labour MP Dover Samuels, of Ngati Kura, said St Morris representatives attended a hui with kaumatua and kuia so a working relationship could be established because of the importance of the Cavallis to the hapu. Since the initial meeting in February there had been no follow-up, Mr Samuels said.
"There's no hostility. We extended a very warm welcome to them ... We are disappointed. It's completely different from [Julian] Robertson, who built the golf course at Kauri Cliffs. Right from the beginning they worked very, very closely with Maori.
"We're not sure who owns the bloody place. We're dealing with overseas phantoms and probably they don't want any publicity ... I can understand that, but there's no way they're going to be under the radar given the significance of those islands."
Mr Han, who has an apartment in Auckland, was not home when the Herald visited.
OIO manager Annelies McClure said the investigation was complex, involving a number of individuals and organisations. She did not put a timeframe on when it would end, saying the OIO was still seeking information and documentation.
Motukawaiti/Step Island
*Sold August 2010. Price paid unclear although thought to be more than $11 million.
*Complex interests in island. Land records note a mortgage to a Jun Zhang, and a caveat by Haiming Jiang.
*Part of the Cavalli Islands, fishing and mutton-birding spot.
*37 ha. Luxury retreat on island.
*Sunken wreck of the Rainbow Warrior a major dive attraction.
*Exclusive golf course Kauri Cliff on the mainland opposite.
*Another major island in the Cavallis is DoC-owned Motukawanui.
*25 remaining islets and rocks making up the island group are a Maori reservation, originally for mutton-birding. Defined as customary Maori land - land without a determination of title.