TORONTO -- Two Asian carp found in contained ponds near Toronto's waterfront this week have prompted three government agencies to rush officials to the scene to determine how the invasive species entered the ponds near Lake Ontario, and whether there are more.

Staff from the Toronto Region Conservation Authority found the first fish on Monday in a pond at Tommy Thompson Park, and the second on Tuesday.

Both fish were male, fertile and likely at least nine years old, but it's unknown where they came from.

Asian carp are notorious for gutting North American ecosystems with their prolific breeding and voracious consumption of other species' natural habitats.

The fish, which include the silver, bighead, grass and black species, have previously invaded the Mississippi river and replaced its native species, prompting the U.S. government to launch a $60-million plan this year to detect and prevent them from spreading to the Great Lakes.

In 2012, the federal government allocated $17.5 million over five years to prevent Asian carp from reaching Canadian waterways.

Officials from Fisheries and Oceans Canada and the Ontario Ministry of Natural Resources and Forestry remained on scene at the Toronto waterfront this week, but warned that the discovery of two fish doesn't constitute an invasion.

The Ontario government considers Asian carp, which can reach more than 40 kilograms in weight and one metre in length, one of the greatest threats to the Great Lakes.

Both fish found this week are dead and have been sent to the United States for testing.