He said Dick Withington, acting head of Gosford Park Primary School in Coventry, had acted in an "totally unacceptable" manner.

"We have a headteacher who has deliberately colluded with parents to keep difficult children out of school during the inspection so that the school gets a better inspection report than it otherwise would," Mr Woodhead told BBC Radio WM.

"It's very wrong if a headteacher is deliberately keeping children away from school in an attempt to pull the wool over the inspector's eyes.

"The lead inspector who is responsible for the report will obviously have to take into account the fact that this has emerged.

"He will have to decide whether or not the picture he has built up of the school's performance is an accurate one or whether or not things have been hidden from him."

Mr Woodhead added that the type of pupils a school had to deal with was taken into account by inspection teams from the Office for Standards in Education.

Apology

Mr Withington has defended his actions and said his was not the only school asking parents to take children out of school during inspections.

Coventry City Council has sent officers to the school to carry out a full inquiry.

The chairman of its education committee, George Duggins, said both pupils had been invited to attend school but as yet had not returned to classes.

"The head, who is an acting head, and who will not be at the school next term, has apologised to the local education authority for his actions," he said.

"The policy of Coventry education authority of not excluding pupils during Ofsted inspections has been fully articulated and we hope made clear to all schools in the borough."

He added that he hoped the school would be allowed to complete its inspection, which is scheduled to end on Friday, without further incident.