Three councillors in South Gloucestershire have apologised for swapping jokes about swine flu as the authority dealt with two confirmed cases of the disease.

The council acted after a complaint that members – including one who represented the ward where a school was shut because of the bug – abused its e-mail system by swapping gags on Friday afternoon.

They did so as council staff, doctors and nurses dealt with the closure of Downend School, which is run by the authority, after a 12-year-old Year 7 pupil contracted the disease while on holiday in Mexico.

The pupil, who has not been named, had returned to school before falling ill and the school has been closed until next Monday as a precaution.

Later it emerged that a second South Gloucestershire resident, 43-year-old Barry Greatorex of Chipping Sodbury, had also been diagnosed with the disease, which he caught from a colleague who had visited Mexico.

Last night the authority issued a statement in which the councillors involved – Tories Janet Biggin, who represents Downend, Justin Howells (Stoke Gifford) and Lib Dem Peter Tyzack (Pilning and Severn Beach) – apologised individually.

A council spokesman, said: "This behaviour is totally unacceptable. The leaders of the Conservative and Lib Dem groups on the council have been informed and have taken appropriate action with their members.

"All councillors must sign-up to policies relating to the acceptable use of council IT equipment."

Ms Biggin said: "I very much regret any offence this may have caused to the local community and in particular to Downend School."

Mr Howells said: "I offer a full and complete apology and deeply regret any offence which I may have caused."

Mr Tyzack said: "I apologise unreservedly."