The Tokyo Metropolitan Government has announced that a person could have been infected with a coronavirus variant that has not been previously detected in Japan outside of airport quarantine stations.
Officials said on Friday that experts at the Tokyo Metropolitan Institute of Public Health found the virus in a sample from a man in his 50s who returned from North Africa in mid-May.
The officials say no one came into close contact with the man, and that his medical treatment has been completed.
They say the sample may have a deficiency in part of its spike protein with the L452R mutation.
The officials say the variant has been confirmed in 34 countries, including Germany, the United States and Britain.
They say they will continue genome analysis of the virus, in cooperation with the central government.
The Metropolitan Government also reported that 28 cases of the variant first detected in India, which has the L452R mutation, have been confirmed so far in Tokyo.
It also said that people infected with variants with the N501Y mutation account for 83 percent of new cases, up by about 1 percentage point from the previous week.