He said Mr Gorbatchev, a businessman, introduced himself as "Brad" and insisted they move in on December 17.
The man claimed his parents were approached by two women, including one who identified herself as Mr Gorbatchev's former wife, when they tried to move into the property on December 19.
Both women, he claimed, said his parents could not move in because of the matrimonial dispute and that the house would be sold.
Work and Income advised the couple not to move in and asked Mr Gorbatchev for a refund but he declined.
"This story needs to go out so that people are more aware of who they are dealing with.
The current housing market means it's a sellers' market," the couple's son said.
Mr Gorbatchev claimed the property would not be sold and insisted he was the sole owner of the house. He said nothing should have stopped the elderly couple from moving in.
If his ex-wife came to the house when the elderly couple moved in, he said the new tenants could call police.
The Ministry of Social Development's regional director, Graham MacPherson, said the government department did not have legal powers to check the status of a house before making payments for bond and advanced rent.
The ministry, he said, sympathised with the couple who have found themselves in a stressful situation through no fault of their own.
Mr MacPherson said in rare instances such as this clients needed to seek resolution through the Tenancy Tribunal which has legal powers to order landlords to return the funds.
The ministry has referred the couple to the Community Law Centre and also helped them extend the lease of the property they were currently renting, he said.
"Prospective tenants need to be sure as far as possible that the property they are moving to is suitable and that their landlord is reputable."
It's not the first time the Weaver St property has hit the headlines. In November a man who rented the property from Mr Gorbatchev moved out after little more than 24 hours.
During that time his flat got invaded by a club-wielding man, the flat below got smashed up and his landlord couldn't come to help as he'd been trespassed off the property by a previous tenant.