Sir John Key jokes about skyrocketing house prices in surprise charity appearance

Former Prime Minister Sir John Key made a wisecrack about New Zealand's skyrocketing house prices during a surprise appearance in a charity talkathon. 

Sir John appeared in Magic Talk's 36-hour talkathon to raise money for child cancer on Thursday. 

Sir John made the joke while suggesting host Ryan Bridge shave his head if they raise $100,000 for the Child Cancer Foundation. 

"Ryan we know that you're a man of sartorial elegance and that man bun is very important to you, so if we can get to $100,000 which is pretty easy, I mean house prices will go up that much by the time we finish the conversation and that's just your house, then you will chop it off I reckon," Sir John said. 

Bridge seemed keen on the idea although he questioned why Sir John would want to "deprive the world of such beauty?".

Sir John hit back saying Bridge could always grow it back, unlike him. 

"It's raising money for a great cause and you can grow it back, it's a beautiful thing unlike me who could not grow one back."

Sir John's quip comes after record growth saw house prices up 28.7 percent in June compared to the same time last year. 

Figures from The Real Estate Institute of New Zealand (REINZ) June property report, released on Tuesday, also showed the national median sale price hit $820,000. Compared to the previous month (May), the national median price is up by 0.3 percent. 

The steady increase comes despite the Government introducing a range of changes in March in an effort to dampen the overheated market. 

The changes included the removal of interest deductions on investment properties - a move that made owning multiple homes significantly less lucrative.

The Government also increased the caps for first home grants in an effort to help first home buyers into the market. 

But so far the changes seemed to have had little effect with five regions hitting new price records in June. The regions were Auckland (up 25 percent year-on-year), Waikato (up 19.7 percent), Taranaki (up 41.5 percent), Marlborough (up 56 percent), Southland (up 23.2 percent) and Manawatu/Whanganui (up 35.6 percent).