The family of a teenage student who was filmed having sex by his teacher during a school trip are seeking legal advice to try and enforce a life ban from teaching on the school master.

Former Shrewsbury School teacher Michael Clarkson was struck off the teaching register earlier this week following a General Teaching Council conduct committee hearing in Birmingham.

He is now ineligible to apply to register as a teacher again for at least four years.

But the step-father of the student, who was 17 when the incident happened in Portugal two years ago, said he did not believe the length of the ban was sufficient.

The step-father, who cannot be named for legal reasons, said: “We are taking legal advice in relation to the decision and whether there is a possibility of having the length of the ban increased or stopping him from being able to re-apply.

“We’re also taking legal advice because with the GTC having found that he held a duty of care to the pupils we want to know whether there is a right of action against Shrewsbury School as well.”

Mr Clarkson, who is in his 30s, was found on Wednesday to have behaved in a manner that had amounted to unacceptable professional conduct during the tennis training camp trip to Portugal in April 2006.

The teacher admitted condoning a 17-year-old pupil to use his bed to have sex by not discouraging the act. He also admitted taking pictures of and setting up a video camera to record the pupil while in the bedroom.

He also failed to ensure a reasonable curfew, allowed students to consume excessive amounts of alcohol and was under the influence of alcohol himself on the final night of the trip.