Teachers at schools that were at the centre of last year’s ‘Trojan Horse’ scandal are receiving death threats, with dead animals being left outside school buildings.

The Daily Mail reports that head teachers are blaming the renewed campaign of intimidation on hardline Islamists who oppose the strict measures introduced to clamp down on attempts to radicalise students.

Speaking at the annual conference of the National Association of Head Teachers (NAHT), Sarah Hewitt-Clarkson, principal of Anderton Park School in Birmingham, said: “Trojan Horse has not gone away. Those of us who were involved, we knew it was the tip of the iceberg.

“We still have dead animals hung on the gates of schools, dismembered cats on playgrounds. We have petitions outside schools, objecting to teachers teaching against homophobia.”

She also claimed to have received death threats on Facebook after organising a talk opposing homophobia, with one person saying: “any headteacher who teaches my children it’s alright to be gay will be at the end of my shotgun.”

The Trojan Horse scandal broke last year when an anonymous letter described a campaign by Islamic hardliners to install themselves as governors of secular state schools in Birmingham and then replace staff with teachers more sympathetic to an Islamist agenda.

Although the letter is now believed to be a hoax, it led to 21 schools being inspected, with six being put in “special measures” and five accused of not doing enough to tackle extremism.

Anderton Park School, of which Sarah Hewitt-Clarkson is head, was one of the schools investigated, with school governors allegedly discussing plans to impose an “Islamising agenda” on WhatsApp.

The government also commissioned a separate report, known as the Clarke Report, which found evidence of an “aggressive Islamist agenda” at some schools and recommended stricter checks on people who want to be school governors.

The NAHT has raised concerns, however, that recommendations preventing certain people from being involved in running schools have not been acted on.

NAHT senior regional officer Rob Kelsall said: “That has left the door open and allowed the resurgence of some of the key operators to try and start to intimidate some of the headteachers who are not necessarily the ones who are going to be speaking out.”