Health officials have defended the testing as a surveillance measure that helps fill an information gap from China.
The national COVID-19 recovery rate was recorded at 98.54 per cent, the health ministry said.
In fact, all the 13 districts have reported a spike in positivity rate when compared to the previous week.
Delhi recorded 928 fresh COVID-19 cases, lowest in over a week, with a positivity rate of 7.08 per cent and three more fatalities due to the viral disease in a span of 24 hours, on Wednesday.
This is for the first time after June 15 that Mumbai saw less than 2,000 daily cases.
While the number of fresh cases has gone down in the last three days, the number of patients admitted in hospitals and in home isolation has increased.
The active cases accounted for 0.04 per cent of the total infections, while the national COVID-19 recovery rate was recorded at 98.74 per cent.
Official sources said that Union Health Secretary Rajesh Bhushan will make a presentation on the matter.
An official said that 44 persons were discharged during the day, which had taken the recovery count to 10,39,105, leaving the city with an active caseload of 474.
Delhi had reported one death and 1,009 fresh COVID cases on Wednesday, the maximum since February 10, with a positivity rate of 5.7 per cent.
As many as 56 patients were discharged from hospitals during the day, taking the count of recoveries to 10,39,061, while the toll stood at 19,562 as no fresh casualties were reported.
The city has been witnessing a rise in infections over the last couple of days, after it recorded 83 and 34 cases on Tuesday and Monday respectively.
Health minister Veena George has accused the Centre of spreading misinformation that the state was not sharing daily Covid data with it.
All the new cases are asymptomatic, and only 10 of the 26,044 hospital beds earmarked for COVID-19 treatment are currently occupied.
While no new death has been reported in the city due to the coronavirus, the city had on Monday recorded 501 cases and zero death while the positivity rate stood at 7.72 per cent.
Kerala government would soon submit a reply to the Centre's letter attaching all the details, state Health Minister Veena George said.
As per updated national-level data on Monday, Kerala contributed 43% of new cases and 99.5% of Covid deaths in the country
With the new cases, the city's infection tally has risen to 18,69,051 while the death toll stood at 26,160 as no new fatality was reported.
The country logged 2,183 new coronavirus infections, taking the total tally of COVID-19 cases to 4,30,44,280, while the active cases declined to 11,542.
With these new cases, the city's infection tally has risen to 18,68,550 while the death toll stood at 26,160.