Mr Lepionka paid a deposit of $463,000 to property development company GLW for several planned sections on the property in 2014.
When GLW defaulted on its $2.6 million mortgage with Westpac Mr Lepionka bought the mortgage off the bank to prevent losing his deposit.
He said he spent $6000 a week on security firms, to prevent former GLW director Garth Paterson from entering the property, but called them off when the Australian was bankrupted in Australia.
Mr Paterson received permission to visit New Zealand a year ago, gaining entry to the house. Mr Lepionka arranged for the electricity to be cut off but the lineman was allegedly bitten by GLW owner/director Liz O'Neil. The former wife of Mr Paterson, she was charged with assault to injure.
Mr Lepionka said Mr Paterson served trespass notices on security firms "so they weren't prepared to go back on to the site".
"We had to find an alternative," Mr Lepionka said.
In November Mr O'Reilly sought legal advice, ascertained the house was unoccupied, engaged a locksmith, hired groundskeepers and moved in.
When Hawke's Bay Today visited unannounced Mr O'Reilly was hosting his grandson's cricket team at the house overlooking the Tukituki River.
"The young fellas I have working here have all had to overcome a problem or two," Mr O'Reilly said.
He said one short-term employee was a former patched gang member.
"It's pretty hard in my community to not have somebody associated with Black Power," Mr O'Reilly said.
"There has never been any insignia on the property. I just won't allow it in any of the dealings I have with anyone."
Mr O'Reilly said he was currently working on projects with two law firms, the Ministry of Health, a courier firm, was chairman of a government-funded anti-drug trust and a marae fundraiser.
"I run a legitimate business and pay my taxes. Sometimes people come to me with unusual problematics."
After high school Mr O'Reilly spent a year at the Marist seminary in Napier, but instead of becoming a priest became a tenancy advocate before joining Black Power.
He said he became the gang's national organiser before accepting a challenge from Prime Minister Sir Robert Muldoon to apply his skills for positive change.
Mr O'Reilly holds a Master of Social Practice degree and is an anti-drug campaigner and programme facilitator.
He said he maintained the Black Power relationship because it enables him to make a social contribution that might "defy others".
"Forty years of successive New Zealand government administrations have found that to be a useful conduit. That's across police, health and social welfare."
Mr Paterson, who is now also bankrupt in New Zealand, did not respond to a request for comment.
