More than half of New Delhi’s 20 million inhabitants may have been infected with the coronavirus, according to a government serological survey whose findings echoed earlier private-sector research.

India has reported 10.8m Covid-19 infections, the most anywhere outside the United States. But the survey, based on some 28,000 samples, suggests the true figure among its 1.35 billion population is dramatically higher and approaching herd immunity levels.

“In the fifth sero survey done in the national capital of Delhi, (coronavirus) antibodies have been detected in 56.13 per cent of the city’s population,” Delhi Health Minister Satyendar Jain said on Twitter after the report was published.

Separate tests done on more than 700,000 people across India by diagnostics company Thyrocare Technologies showed 55pc of the population may have already been infected, its chief told Reuters last week.