Counter-terror police are investigating a new alleged Islamist “Trojan Horse” plot to control a state school, with claims the head teacher was attacked and intimidated by Muslim parents, including a threat to blow up her car.

Almost all the students at Clarksfield Primary School in Oldham are of Pakistani Muslim heritage, and some parents are said to have ordered female teachers to cover their heads. One governor, whose sibling is a convicted terrorist, hosted “Islamic teaching sessions” at the school.

Trish O’Donnell has been the school’s head teacher since 2006 and says the intimidation began in 2013. She has emailed the local council saying she had “very strong reasons to believe that… a ‘Trojan Horse’ agenda [is] being played out”, The Sunday Times reported.

A senior national figure in counter-extremism told the paper there was a “significant problem” of Islamist infiltration in Oldham. “It is an absolute model of entryism,” he added.

The head teachers’ union, the NAHT, said it was “supporting a number of members in the Oldham area with a variety of apparent Trojan Horse issues”.

A confidential report on Clarksfield by Oldham council this month, leaked to The Sunday Times, says Mrs O’Donnell claims to have had been subjected to a lasting campaign of “death threats”, “threats to blow up her car” and “aggressive verbal abuse”. One parent even physically attacked her, the report said.

According to the Manchester Evening News, Greater Manchester Police’s Counter Terrorism Unit are investigating alongside the Council and Department of Education.

The Council report insisted there was no wider ‘Trojan Horse’-style plot, but drew attention to the “extremely problematic” behaviour of former governor Nasim Ashraf and his wife, Hafizan Zaman, who tried to mobilise Muslim parents and admit trying to “remove” the head teacher.

Mr Ashraf’s sister, Shasta Khan, is serving an eight-year sentence for her part in a plot to attack Jewish targets in Manchester. He is also linked to Tahir Alam, the leader of the Birmingham Trojan Horse plot exposed two years ago.

According to the council report, Mr Ashraf hosted “Islamic teaching sessions” on Clarksfield school premises and his wife “made remarks to Asian staff members that they should, as Muslim women, be wearing a veil and covering their heads”.

The couple were not involved in violence or threats, but they organised petitions against the school leadership, opposed Hindu music being played in class and tried to stop “lewd and inappropriate activities” including sex education.

Despite denying this constituted a ‘Trojan Horse’ plot, the report concedes the couple was trying to “intimidate school staff”, “undermine the head teacher” and “secure changes at the school to reflect their interpretation of Islam”.

“It’s my duty to keep an eye on things,” Mr Ashraf told The Sunday Times. “The school is still a failing school – we need to remove Mrs O’Donnell and replace her with a better head teacher.”

Mr Ashraf is also an activist with UK Islamic Mission, whose Oldham branch states on its website that “Allah alone must be worshipped and obeyed… in the courts of law and the corridors of power.”

Ofsted’s latest report ranks Clarksfield school as “good” and praises Mrs O’Donnell’s leadership, insisting she vastly improved English language skills among children and made efforts to teach “British values”.