Andrew Motion, the poet laureate, has become involved in a dispute with a student he teaches on the creative writing MA course at the University of East Anglia, it emerged yesterday.

Laura Fish, the author of a critically acclaimed novel, is alleging that Motion harassed her. She has a series of emails from him which she is expected to present to the university when it formally investigates the matter.

Motion, 48, who is married with three children, has responded by complaining to the university that Ms Fish is harassing him, although he does not deny that he kissed her or sent her personal emails.

It will be down to the university authorities to unravel the dispute. A spokesman said it would take any "appropriate action" after it had formally investigated the complaints.

Ms Fish, 37, enrolled on the one-year course last autumn. It is understood that Motion accepted her because he was impressed by her novel, Flight of Black Swans.

Ms Fish, who lives with her five-year old son on the campus at Norwich, claims that she complained to the university authorities about Mr Motion, but believes she was not taken seriously.

However in a letter to Ms Fish dated December 8 last year, the dean of English and American studies, Jon Cook, says the matters she raised are "of the greatest concern". The dean says he will sit in on tutorial meetings she has with Motion and writes that he has instructed the professor only to contact her in relation to work.

"I will be speaking to Professor Motion about the consequences of his behaviour towards you," he says. "I will warn him that he risks dismissal if he behaves towards others as he has behaved towards you ... I have no doubt he is aware of the seriousness of the situation.

"He will be told emphatically that no repetition of what has happened to you can be tolerated."

It is understood that in January Ms Fish wrote to the dean that she was satisfied with the steps that had been taken and saw no need for further action. But now she is insistent that a full investigation should take place.

Motion, however, claims that he is the victim. In a statement issued yesterday he said: "I have reluctantly been obliged to make a formal complaint to the university authorities about a mature student on the creative writing MA course in which I have accused her of harassing me, and some of her fellow students, and of slandering me to the press and elsewhere."

"It is not appropriate for me to make any further comment while this process is under way in the university. Further legal action is also under discussion at this point."

Motion's wife, Jan Dalley, claimed that Ms Fish had repeatedly telephoned their London home. Ms Dalley, a respected writer and critic who has been married to Motion for 15 years, said teaching creative writing was an "emotional business".

She said those involved in the course could get very "bound up with each other" but the idea that in this case there had been sexual harass ment was "complete fantasy".

She admitted that her husband might not have been wise to visit Ms Fish at her home and may have let her become too close. She said he did not deny that he had kissed her.

A biographer of Keats and Larkin, Motion was appointed professor of creative writing at East Anglia in 1995.

Ms Fish is working on a book about harassment.