The prankster shared emails in which staff discussed doing "dirty work" against US President Trump's daughter Ivanka and her husband, Jared Kushner.

Mr Bannon has returned to Breitbart after being fired from the White House.

"I don't much care for the Trump administration or Breitbart," the prankster told the BBC.

One of the emails purporting to be from Mr Bannon said the former White House chief strategist would be "bringing forth my wrath on Ivanka and Jared".

A reply from Breitbart editor-in-chief Alex Marlow suggested "dirty work" would follow.

He later added that the pair would be "out by end of year".

Fellow editor Joel Pollak replied: "No-one can figure out what they do."

'Deceitful'

In a statement to US broadcaster CNN, Mr Marlow said: "An imposter deceitfully obtained and shared with CNN tongue-in-cheek emails that revealed that we feel globalists present an existential threat to the agenda that got President Trump elected.

"If people want to know our thinking, they don't need to judge us on illicitly obtained comments that were intended to be private, they can simply read our front page."

The prankster tweets under the pseudonym Sinon Reborn - a reference to the figure in Greek mythology who tricked Troy into accepting the Trojan Horse.

"Originally I was trying to get an email address for [Steve Bannon] while he was in the White House, because he seemed like quite a character," Sinon Reborn told the BBC.

When this proved difficult, the prankster said they had decided to try tricking the editors at Breitbart instead.

"I've not really immersed myself in politics prior to [Trump's election]," the prankster added.

"It's like a never-ending soap opera that's on 24/7."

The fake emails purporting to come from Mr Bannon included an incorrect spelling of his name, "Steven" rather than "Stephen", and were sent from "This email address is being protected from spambots. You need JavaScript enabled to view it.".

The prankster added that the messages included an oblique reference to TV comedy character Alan Partridge where at one point the fake Mr Bannon replied: "Lovely stuff."

"I'm a big fan of Partridge and Peep Show - all the British comedy," Sinon Reborn said.