The housing market in Dunedin has slumped, with average prices and sale volumes falling.

The Real Estate Institute of New Zealand says it's been the worst June on record for house sales in Dunedin, outside of the normal January holiday slowdown.

Sale volumes fell 23% compared to last June, and 27% compared to May.

There were 115 sales in the city last month, and the institute says that's due to a lack of new property on the market.

The median price for houses fell 4%, down $10,000.

That put the median house price for Dunedin at $260,000.