A school once ranked as outstanding but which went into special measures after going through 10 headteachers in three years has lost yet another head.

The sudden departure of Darren Kenyon from Dunmore Junior School in Abingdon on "indefinite sick leave" is the latest example of the struggle to recruit - and keep - heads at Oxfordshire schools.

Earlier this year it was revealed that seven schools were seeking a new head, including two posts that had been vacant for more than five months. Twelve schools had acting heads.

Parents of children at Dunmore School said they were devastated by the loss of Mr Kenyon at the end of last term.

Mr Kenyon, who took over permanently in April last year following a succession of temporary heads, is on "indefinite sick leave" and has been replaced by Martin Lester, an advisory head for the local authority, who led the recent turn-around at Windale Primary School in Oxford.

It is understood four heads of year will also leave this summer.

Aileen Jones, 40, of Sellwood Road, Abingdon, whose daughters Abigail, 11, and Melanie, six, are pupils at the school, said children and parents were deeply unsettled about the switch.

She said: "The governors asked us to get 100 per cent behind Mr Kenyon, which we did.

"He was doing a very good job in our eyes and the children loved him. He was approachable and he knew all the children's names within a week.

"Suddenly he's gone, this new person's arrived and he's saying we're not allowed to talk about the past - it's not fair on parents. We don't feel we've had our say.

"Mr Kenyon disappeared just after the SATs tests and it just seems he's been pushed out.

"This new head's just come in to turn it around and then he'll leave again. Mr Kenyon was going to stay and become part of the community."

Roy Leach, a senior schools advisor for the county, said it was unclear whether Mr Kenyon would be back.

He told the Oxford Mail: "We have deployed at short notice Mr Lester, who is a very experienced, highly competent headteacher. He has an excellent track record in securing rapid improvement."

Dunmore was on Ofsted's list of outstanding schools in 1998 and was once one of the Government's beacon schools, receiving extra money to share good practice with other schools.

Following the retirement of Eric Bird in 2000 after 18 years, governors at the 300-pupil school in Northcourt Road spent several years searching for replacements.

An Ofsted report, published in January, failed the school in nine out of 25 categories - including the achievement and progress of pupils - and blamed the leadership changes.

But the inspectors were confident in Mr Kenyon and said he had raised morale at the school.

Clive Hallett, Oxfordshire secretary of the National Association of Head Teachers (NAHT), said the school acted against the advice of the union and the local authority by having a rota of assistant heads in charge in 2003.

He said: "It's desperately sad that such a good school has been through such a long period of upheaval. It was all down to the previous governing body's failure to appoint a permanent head, despite having some very strong applicants to choose from."

He said the problem with recruiting and keeping headteachers was a national problem, with many vacancies receiving just one or two applications.

Mr Lester was unavailable for comment.