Conspiracy theorists claim the hand signals are used by members of the Illuminati – an alleged secret society of world leaders conspiring to control world affairs.
Prime Minister Theresa May and Russian leader Vladimir Putin were also spotted making peculiar gestures with their hands.
Skeptics may well rubbish these supposed gestures as meaningless natural body language.
But conspiracy theory website illuminatiRex lists the hand signal used by Trump and Merkel as an Illuminati signal called the “Merkel-Raute” on its website.
Theresa May sat next to Trump at the G20 Summit
It is claimed celebrities such as Ben Stiller and Tom Cruise, as well as historical figures including Pope John Paul II and Adolf Hitler, have been pictured using the hand signal.
The illuminatiRex website states: “The pyramid is an important Illuminati symbol showing their few ruling the many on the bottom type power structure.
“The symbol becomes more powerful when the sign is done over an eye, representing the All-Seeing eye in a capstone floating over an unfinished pyramid.
“The pyramid sign is seen by many researchers to be THE sign of the Illuminati.”
Trump and Merkel were captured appearing to do the “Merkel-Raute” at the G20 Summit today.
Billionaire Trump, 70, is famous for his outrageous speeches, many of which see him making expressive gestures.
The former chairman of the Trump Organisation has previously been pictured pinching his thumb and index finger together in a pose supposedly symbolising the devil.
This is hand sign supposedly represents 666, meaning “number of the beast” – commonly known as the devil – in the New Testament of the bible.
Trump has also been snapped flicking the devil horns hand gesture usually associated with rock music.
Many of the world’s richest and most powerful people – including former US presidents George Bush and Barack Obama – have been pictured striking these poses, it is claimed.