Secretary of the State Veterinary Surgeons' Association, Nuwan Hewagamage, said on Thursday that the 12-year-old lioness 'Sheena' had tested positive for the virus following medical tests performed on her after the male lion called 'Thor' was infected last week, reports Xinhua news agency.

The 11-year-old 'Thor', which was gifted by a zoo in Seoul in 2013, has become the first known case of an animal contracting Covid in the island nation.

He however has recovered after medical treatment, health experts said.

Thor's keepers were requested to be quarantined for two weeks.

According to authorities, all staff members of the Dehiwala Zoological Garden were subject to a Covid-19 test on June 18.