Human rights activists are calling on Greek authorities to investigate a “shocking” video appearing to show a man aboard a Greek coast guard ship deliberately trying to sink a boat filled with refugees.

The video, recorded by the Turkish coast guard in waters between Turkey and the Greek island of Leros on Nov. 12, was obtained Friday by Middle East Eye.

The footage appears to show a man -- dressed in a uniform worn by Greek coast guard members -- poking at a rubber dingy with a boat hook as refugees on the boat are shouting for help.

A section of the video filmed using night-vision technology shows air exploding out of the dinghy. The boat can then be seen sinking as refugees are picked up by members of the Turkish coast guard, the Middle East Eye reported.

“The Turkish coast guard regularly films its rescue operations, and has previously shared footage with international media,” a government official – who spoke on condition of anonymity – told the Middle East Eye. “But this is shocking. We expect that this footage will be investigated -- it’s difficult for us to understand why they would try to sink a refugee boat.”

Amnesty International said Friday that it was "profoundly concerned" with the video and urged Greek authorities to conduct a "prompt, thorough and impartial investigation into the incident.”

But Greece’s coast guard said it did nothing wrong.

“There is no reason to deny the real event that members of the crew tried to draw near to their large vessel a small inflatable craft by using a nautical hook (that is, a tool used in accordance with international shipping technique and practices for this purpose) while a nearby Turkish coast guard vessel assisted the rescue operation by lighting and facilitating all of the actions with a spotlight,” the coast guard said in a statement.

It added that Greece has helped save about 90,000 refugees to date.

“We believe it to be at the very least contradictory to allege that the Hellenic coast guard supposedly follows such practices, which are incompatible with the values of our culture and which are condemnable at a time when the Hellenic coast guard, from early 2015 until today, has saved some 90,000 refugees from the sea in search and rescue operations.”