Oxford University is devising a code of conduct to clamp down on rowdy antics by students celebrating the end of their final exams.

Thames Valley Police recommended the move after being shocked by the behaviour of students last year.

On-the-spot fines of up to £70 could be levied for offences such as "fluid spraying or egg hurling", while more serious offences such as daubing university buildings with graffiti could be punished with a £500 fine or arrest.

Police say the responsibility for deciding if fines should be issued will remain with university marshals. Recent japes include filling buckets with pigs' offal and tipping it over the heads of fellow revellers.

The code, which will apply within a six-mile radius around Oxford city centre, is subject to final negotiations between the police, the university, the students' union and the city council. If it is backed by the students' union next week, a copy of the code will be sent to all undergraduates.

It proposes a scale of fines from £30 for squirting "silly string" or spraying sparkling wine up to £70 for pranks which could be dangerous, such as hurling eggs at passers-by or using high-velocity water pistols.

Supt Keith Ringsell said: "The code simply reminds them what is and isn't acceptable under their own university rules which they sign up to upon joining Oxford University. In actual fact, we do not police the event at all -- it is supervised entirely by the university marshals and members of the students' union, and we would only become involved in very extreme circumstances.

"We ask that they consider the views of those living in and around the Merton Street area, who may not appreciate waking up to buckets of pig's offal on the street or being pelted with flour and silly string on their way to work."

University spokesman Ruth Collier, 25, an English graduate of University College, said: "When I graduated my friends threw glitter on me, so I would have been within the Code of Conduct.

"We really want students to enjoy themselves because they work incredibly hard but we do not want them to do it in such a way that disturbs other students or local people."