Prague  - A middle-aged Czech woman, who died in hospital Thursday, is suspected to have been the country's first case of a swine flu-related death, a hospital spokeswoman said.

Further tests are to confirm on Friday whether the patient was infected with the H1N1 influenza virus, CTK news agency reported, citing a spokesman for the Czech Ministry of Health.

The woman was initially hospitalized with a serious chronic illness in western Czech city of Karlovy Vary, hospital spokeswoman Zdenka Markova said, declining to give details.

As her condition worsened, she was diagnosed with the H1N1 virus and later died, the spokeswoman said. "The virus complicated her health condition," she said.

According to the Czech health authorities, 309 people are currently known to have been infected with the virus since the first case was registered in the Czech Republic on May 25.

As of October 11, the World Health Organization registered 399,232 confirmed swine flu cases worldwide and 4,735 confirmed deaths.(dpa)