On Sunday, Balakrishnan' blood pressure fell and he suffered multiple organ failure.

'The symptoms shown by the child were not those of swine flu. Failure of organs depends on the immunity of a person. If the immune system is weak, the organs will fail,' said Shanmugasundaram, another doctor at Mehta Children's Hospital.

'The cause of death will have to be investigated as the boy was suffering from asthma and several of his vital organs failed,' S. Illango, director of public health and preventive medicine department, told IANS.

He said the body will soon be handed over to the family for the last rites.

P. Kuganathan, the municipal health officer, said: 'The deceased boy's brother is admitted in the Communicable Diseases Hospital and is free from complications. Other members of the family have tested negative.'

He said that 138 people in the city were tested for swine flu and 45 were positive. Of them, 31 were treated and discharged.

According to a central government health official, 42 people have tested swine flu positive in Tamil Nadu but no case has been reported in nearby Puducherry.

'We are taking all preventive steps like creating awareness. All hospitals will be given Tamiflu tablets. Preventive medication is being given to the people who came in close contact with the boy who died in the morning,' he said.

Meanwhile, two people in Tiruchirapalli and five in Coimbatore have been admitted in government hospital with swine flu symptoms.