A hoax email which threatened to wreck Sunday’s Trafalgar Square rally is being investigated by police.

The email was sent out on Friday, shortly after Shabbat had started. Communal figures, who became aware of the email, believe it was timed so that Orthodox supporters who were planning to go would not see it until after Shabbat ended, and would not turn up.

The hoax started as a bogus email poll, supposedly from CNN. Recipients were asked to vote and their response was used to create a database, which was then used to send out an email, purportedly from the Board of Deputies, one of the rally organisers.

Zionist Federation vice-president Jonathan Hoffman, one of those involved in scuppering the attempted hoax, said: “The wording on the email was incredible. There had been a lot of communal discussion about the rally and, having organised it, there was no way the Board would call it off. That, and an incorrect email address, told us it was a hoax.”

Board chief executive Jon Benjamin said: “The response was phenomenal. Communal professionals and organisations sprang into action to get the word out that the rally was going ahead.”

A complaint was made to police in Barnet, who launched an investigation that led to the arrest of a 22-year-old man on Saturday afternoon. He was later released on police bail to return to a north London police station. A number of items relating to the investigation were seized.

An email sent to the JC, allegedly by the maverick group, Jewdas, claimed responsibility. “Well yes, it was us. We sent the Board of Deputies Hoax email. Not some ‘Islamist cell’ or ‘Hamas supporters’ as many of you imagined.”

Extracts from the hoax email

“The Board of Deputies and the Jewish Leadership Council, in consultation with a coalition of prominent organisations in the Anglo-Jewish community, have decided to cancel the planned Israel Solidarity Rally…. This decision has been taken after intense discussions within the community, due to a feeling that such a demonstration would not be in accordance with the Board’s wish to bring the conflict to an immediate conclusion. It was thought that the demonstration might be perceived as the community taking one side in the tragic war…The Jewish community does not wish to be seen as a participant in the conflict, and in taking this stand we hope to be a part of the solution. The Board stands in solidarity with the besieged and injured people of Gaza…