Conspiracy theorists think Prince Harry made a sign for the devil when he met Melania Trump

Prince Harry met with Melania Trump in Toronto on Sunday 23 September, before the Invictus Games, a Paralympic event Prince Harry helped found for veterans and those in the armed services.

Melania Trump said in a statement:

In just two short years, the Invictus Games have allowed thousands of injured and wounded servicemen and women from many different countries to participate in adaptive sports competitions -- something that should be lauded and supported worldwide.

I am honored by the opportunity to represent our country at this year's games.

The 20 minute meeting between the two started the internet on what it does best: forming a conspiracy theory.

In photos, it looks like Harry is making a devil sign with his hands - a sign of the horns.

The gesture has been diluted over decades through popularised usage, such as at rock concerts - it's been famously used by KISS frontman Gene Simmons.

There is also a counterpoint to be made that cameras can pick up on the quickest moments.

But in a video clip, he looks to be holding the post for a rather long time...

More: Prince Harry tries the old 'shoulder tap' prank on a schoolboy - and fails spectacularly