Children should not be given the antiviral drug Tamiflu - also used to treat swine flu - because its harms outweigh any benefits, a report said yesterday.

Oxford University researchers found Tamiflu caused vomiting in some children, which can lead to dehydration and complications.

The drug also had little or no effect on asthma flare-ups, ear infections, or the likelihood of a youngster needing antibiotics, the British Medical Journal reported.

Co-author Dr Carl Heneg-han, a GP and expert from the John Radcliffe Hospital in Oxford, said the policy of giving Tamiflu for mild illness was an "inappropriate strategy".

He suggested children with mild symptoms should be treated as if they had any other flu - with drinks to cool high temperatures and rest, with no need for children who were otherwise healthy to be taking Tamiflu or Relenza.

He said: "The downside of the harms outweigh the one-day reduction in symptomatic benefits."

However, other biomedical scientists said the study had "limitations" and questioned whether the research, which looked at the effects of the drugs on young sufferers of ordinary seasonal flu, could apply to the current outbreak.

The new report comes a week after other research found children given Tamiflu preventatively reported side-effects, including nausea and nightmares.

Experts at the Health Protection Agency (HPA) showed a high proportion of British children reporting problems after taking the antiviral preventatively.

In one study, the most frequently reported side-effect was nausea, followed by stomach pain or cramps and problems sleeping.

Gastro-intestinal side-effects - nausea, vomiting, diarrhoea, stomach pain and cramps - were reported by 40% of the children.

That research was carried out in April and May - before the government decided to stop using Tamiflu to contain the spread of the virus.

The authors of yesterday's paper said that, while the prescription of Tamiflu and other anti-virals for children could be counter productive, parents should be on their guard for potential complications and signs their child is getting ill.

Parents of children with weakened immune systems, or conditions such as cystic fibrosis, should discuss their options with their GP, the report said.

Dr Matthew Thompson, a GP and co-author, added: "I think what GPs should do is to weigh up the risks and benefits with the parent."

He said the only benefit found in the study was that children got back to normal half a day to one day earlier if taking Tamiflu or Relenza.

His advice to GPs was "not to rely on Tamiflu as a treatment to reduce complications" or to think of it as a "magic bullet", and he warned widespread use of Tamiflu could result in the virus becoming resistant to the drug. He said: "Going forward We have a treatment which is ineffective because we've given it to everybody."

Both researchers called on the Department of Health to review its current policy.

However, a department spokesman dismissed the claims that the findings would also apply to swine flu.

Meanwhile, reports that a million Scots children would be the first in Europe to get the swine flu jab when they return from their summer break have been played down by the Scottish Government.

It was claimed that under-16s would have two doses of the vaccine three weeks apart in a mass immunisation programme.

Westminster confirmed last week that ministers are considering plans to immunise every schoolchild in the UK but said no decision had yet been taken. But a Scottish Government spokeswoman said there had been no change in its stance that the vaccine would start arriving in the autumn.

A first phase of vaccination would involve those groups deemed to be at most risk, with children and young people and health workers likely to be in that group, she said.