A Mumbai police additionalcommissioner was quarantined as a precautionary measure after his reader tested positive for the novel coronavirus, an official said on Sunday.The reader, an inspector rank officer, was detected with the virus on Tuesday after which he was admitted in Kolekalyan police hospital in Santa Cruz East."After the reader tested positive, four persons, including the additional commissioner and an inspector, have been quarantined for 14 days as a precautionary measure" the official said.The personnel who tested positive told PTI he was asymptomatic but was asked to undergo the test by his superior."I was shocked when the report returned positive," he said.