The Toronto Real Estate Board says there is fresh evidence indicating that speculation and foreign ownership make up a small component of the city's housing market, raising questions about the need for Ontario's plan to tax foreign speculators.

The board released new data on foreign buyers at the same time as it reported that prices continued to soar last month, though there were signs the market may be cooling as the number of transactions slipped.

The new data came as the average price for all properties in the Greater Toronto Area last month rose to $920,791, an increase of 24.5 per cent compared to a year ago.

That was slightly below the 33.2 per cent year-over-year increase in prices in March.

TREB says there was a dramatic increase in the number of new listings, which rose by 33.6 per cent since April 2016.

But it also found the total number of sales in the Greater Toronto Area in April was down by 3.2 per cent from a year ago.

TREB says that between 2008 and April 2017, the average share of foreign buyers of properties in the Greater Golden Horseshoe region, which stretches from the Niagara Region to Peterborough, Ont., was 2.3 per cent.

It says during the same time period, the share of homes that were bought and sold within one year of the original transaction -- an indication of speculative activity -- was also low.

In 2016, less than five per cent of transactions fit that definition, while in the first four months of this year, it went up to seven per cent.

TREB says its analysis was based on property assessments and land registry data in the province.