Labour leader Andrew Little used his first house to highlight how housing had become unaffordable under the National-led Government.
However, analysis shows the value of his "starter home" in Wellington rose at a greater rate under a Labour Government than under National.
In his speech at Labour's Congress on Sunday, Little said house prices were "out of control" and getting further and further out of reach for Kiwi families.
He spoke about he and his wife Leigh's first home, a two-storey property in Brooklyn which cost $315,000.
"That wasn't a small amount of money for us, but it was manageable. It got us a three-bedroom starter home, built on a hillside in Wellington."
"Now, it would cost around $830,000. It's gone up by half a million dollars in 17 years.
"Its value has nearly tripled. But here's the thing: Families' incomes haven't tripled since 2000. Nowhere near."
Little sold the house two years later for a profit of $40,000.
According to estimates about the Brooklyn property's value by research firm CoreLogic, it is now worth around $845,000 - even more than Little suggested.
CoreLogic's estimates also show that the property's value rose at a greater rate under Labour than under National.
Under Labour, it rose by $255,000, or 81 per cent. Since 2008, when National came to power, it has risen by 48 per cent, or $273,000.
Little wouldn't comment, but his office said the story highlighted the current problem and the need for a solution.
The Labour leader now lives in Island Bay, in a house which is valued at $920,000 on the website Homes.co.nz.
A housing affordability index published for the first time last week showed that the share of people struggling to get into a home was similar under the previous Labour Government and the current National Government.
However, the level of people who had to go into financial hardship to buy a home in Auckland had risen to its highest level under National, in 2015. The Ministry of Business, Innovation and Employment index showed 86 per cent of Auckland renters could not buy a home in 2015 without going into hardship.
Labour is promising to address affordability problems by building 100,000 mid-priced houses in 10 years, banning purchases by non-residents, and extending a "bright line test" to five years. It announced on Sunday that it would get rid of a tax incentive for landlords which it said encouraged speculation.
National is aiming to boost supply by redeveloping Crown land with capacity for 70,000 homes, while also building houses on fast-tracked housing areas and offering grants of up to $20,000 for first-home buyers.