Thousands of janitor fish were found dead after being washed onto a path during a typhoon in the Philippines.

Footage shows the large black fish lining the banks of Marikina River that had reached critical levels at the onslaught of Typhoon Gaemi in the capital Manila on July 26.

They were found by residents who went to the area after the flood that submerged the area receded.

Local Kuya Lev said in the video: ‘I will show you how much janitor fish died here. Their heads are massive. There are so many.'

The invasive species, native to the Amazon, was believed to be introduced to local rivers by irresponsible pet owners who released them once the fish outgrew its colourful fins.

Typhoon Gaemi killed 22 in the Philippines after lashing through mainland Luzon for almost a week, intensifying monsoon rains. It headed to Taiwan killing three people and injuring more than 200 when it made landfall.