Pepe the Frog
Pepe the Frog has been adopted in memes by the 'alt right' movement, which has rallied around US presidential candidate Donald Trump via Twitter

Popular internet meme Pepe the Frog has been listed as a hate symbol by the US-based Anti-Defamation League.

The anti-racism organisation, which monitors far-right and Neo Nazi hate speech in the US, said the symbol did not always have racist connotations, but it had been adopted as a symbol by the 'alt-right' movement.

The cartoon frog originated in the 2005 comic Boy's Club, and took off as a meme on the message board 4Chan.

It has been used by supporters of the alt-right movement to express anti-Semitic, Islamophobic and other forms of racist hatred through memes on social media.

"The Pepe the Frog character did not originally have racist or anti-Semitic connotations," the ADL said in a statement. "Internet users appropriated the character and turned him into a meme, placing the frog in a variety of circumstances and saying many different things.

"The use of racist and bigoted versions of Pepe memes seems to be increasing, not decreasing."

The ADL provided several examples of racist use of the character, which is now listed alongside racist symbols including the swastika and the Confederate flag. They include Pepe the Frog wearing a Klu Klux Klan hood, and Pepe the Frog with a Hitler moustache.

The alt-right movement presents itself as a populist alternative to US mainstream conservatism, and has rallied around Trump and his anti-immigration, anti-Islam views. Supporters of the movement have used memes, internet messaging boards and social media to promote racist and white supremacist views.

Pepe's creator, Matt Furie, has said that he believes the use of by racist groups will pass.

"I think he's on a weird manifestation right now," Furie told the Washington Post, "It's unfortunate that he's peaking nationally in the news in this really negative way, but I think it's just a phase."