TAIPEI， Oct。 28 （Xinhua） —— Taiwan‘s epidemic monitoring agency admitted Wednesday that a Taiwan businessman， who returned from the Chinese mainland on Oct。 11， was diagnosed with COVID-19 by mistake。

The testing lab had mixed up his sample with another Taiwan resident who returned from France on the same day and also took the COVID-19 test， the agency said in a press release。

The man from France developed symptoms during his quarantine and was diagnosed with the disease days later， the statement said。

The agency also announced that it has received notices from Japan and Thailand about three people who tested positive for the virus shortly after leaving Taiwan and has started investigations。

Meanwhile， one Indonesian national tested positive for the virus in Taiwan Wednesday， raising the island’s total number of infections to 551， the agency said。 Enditem