A Covid-19 patient who alleged that she could have been infected at Changi Airport after arriving from Nepal on April 25 was unlikely to have caught the virus in Singapore.

The Ministry of Health (MOH) said yesterday that its investigations have confirmed that the woman's infection is not related to those in the Changi Airport Terminal 3 cluster.

MOH was responding to queries from The Straits Times on claims made by Ms Sonal Wadde, a 32-year-old Indian national and dependant's pass holder, that she felt safer in India.

A screenshot circulated online shows she had written, in response to a question on Facebook, that she was infected "most probably" at Changi Airport.

This was because two polymerase chain reaction tests that she took before boarding the flight to Singapore and upon arrival had been negative, she wrote in the comment, which was picked up by several online news websites.

It is unclear when she posted the comment or what question she was responding to.

MOH said: "A negative pre-departure test or on-arrival test does not necessarily mean that a person is free from Covid-19, as one could be incubating the virus from an exposure prior to taking the tests."

The Changi Airport cluster is currently the largest active cluster, with 108 cases linked to it as at Thursday.

Ms Wadde is an imported case who was confirmed to have a Covid-19 infection on May 2, said MOH. Her infection was detected when she tested positive during her stay-home notice period at a dedicated facility.

After she was identified as a DBS Bank employee in online articles on Tuesday, the bank clarified in a Facebook post that she was previously engaged as a contract employee through a third-party vendor from June to July 2019. Ms Wadde is not currently a DBS employee, said the post.

"We hold our employees to the highest standards of conduct, both in person and online. DBS is fully committed to supporting the national effort to contain the spread of Covid-19," said the bank.

Checks by ST found that Ms Wadde's LinkedIn and Facebook profiles were no longer accessible.