A Muslim boarding school that threatens to expel students for mixing with "outsiders" has been rated "good" by Ofsted.

In its most recent report, the education watchdog praised the Institute of Islamic Education in Dewsbury for preparing its pupils for the changing needs of British Muslims.

But according to documents handed to parents, seen by Sky News, pupils are forbidden from "socialising with outsiders" and face "expulsion if there is no improvement after cautioning".

The school also provided a Pupil and Parent Handbook which contained a Sharia law section warning that having portable televisions or cameras is forbidden.

The Institute is housed in Dewsbury’s Markazi Mosque compound and is run by the strict Tablighi Jamaat sect.

A mosque elder, Shabbir Daji, told Sky News the school "works for unity" but would not discuss the restrictions saying the school had a policy of "keeping away from the media".

In a statement, Ofsted said independent schools were not assessed on their teaching of "British Values" when the school was last inspected.

New tougher rules to combat extremism were introduced by Ofsted in April 2015 in the wake of the Trojan Horse scandal where a group of hardline Muslims were alleged to have plotted to take control of certain Birmingham schools.

An Ofsted spokesperson said: “We were last asked to inspect this school in 2011. By law Ofsted can only inspect independent schools at the request of the Department for Education.