Given the public speculation on whether Leave.EU had been involved with the botnet the researchers discovered, BuzzFeed News asked Wigmore on Tuesday what use the campaign had made of bots, and whether any such use had been disclosed in the campaign's spending returns, as required under UK election law.

In a bizarre and occasionally abusive response, Wigmore strongly denied any use of bots by Leave.EU, and said his tweet had been "sarcasm".

"You are either very very very young or a complete idiot … it’s called sarcasm!!!" Wigmore wrote. "Get a grip.....

"No bots were used by any of the Leave teams and bots make Zero difference on anything - you and the likes of Carole and other anti Trump idiots have zero understanding of technology if you honestly think any kind of bot works or can hypnotise the electorate in anyway. Next you will be telling me Elvis is alive and well and living in Croydon, David Cameron is a lizard and Nigel Farage is in fact gay."

Senior former staff of the official Vote Leave campaign told BuzzFeed News on Friday their campaign had made no use of Twitter bots, leaving open the question of who was behind the suspected botnet uncovered by the City University researchers.

Damian Collins, the head of parliament's culture, media and sport committee, wrote to Twitter in the wake of BuzzFeed News' revelations to ask for more information on Brexit-related bot activity. On Tuesday the committee wrote to Facebook to ask for any information the social network has in relation to suspected Russian influence on either the Brexit vote or the general election of 2017.

Separately, Labour MP and former cabinet minister Ben Bradshaw has publicly called for a parliamentary inquiry into possible Russian influence on the Brexit vote.

Here is Andy Wigmore's statement to BuzzFeed News in full: