Omicron along with one of his contacts - a 36-year-old female friend who arrived in the city from the US the same day. For now, the patients have been admitted to BMC-run Seven Hills Hospital in suburban Mumbai.
The BMC said it carried out COVID-19 tests on all the close contacts of the two travellers, but none of them tested positive for the infection.
The civic body has been carrying out COVID-19 tests on international travellers arriving in Mumbai since November 1. So far, 16 travellers - 12 males and four females - have tested positive for COVID-19.
Swab samples of all of them were sent for genome sequencing and one of them (37-year-old returnee from South Africa) was found infected with Omicron, the civic body said.