The baby was discovered wrapped inside a plastic bag and left abandoned near a construction site in Bengaluru's Electronic city, reported The Hindu.
Assistant Sub-Inspector Nagesh R was the first police official to arrive at the scene. "The baby was in bad shape. He was covered in blood and the umbilical cord was wrapped around his neck," he told The Hindu.
Mr Nagesh took the baby to a nearby hospital, where doctors treated him for free. He then brought the infant to the police station.
Ms Archana, mother to a three-month-old boy, had recently returned to work after her maternity leave. She picked up the baby and breastfed him.
"I just couldn't bear it," Ms Archana told BBC. "I felt like my child was crying and I had to feed the baby."
The newborn then was handed over to Shishu Mandir, a children's home in Bengaluru.
On Wednesday, the Karnataka Chief Minister tweeted he was "deeply moved" by the news and would meet the police constable "who nursed the little one to life" to express his gratitude.
Bengaluru City Police hailed Ms Archana on Facebook. "We salute the Mother in our Lady Police Constable Archana of Bangalore City Police who rescued an abandoned new born and breastfed the infant, she had just returned from Maternity Leave (sic)," they wrote in the post, adding the hashtag #ThankYouArchana.
Immediately, praise poured in for Ms Archana. "Lots of respect to you madam," wrote one person. "Long live humanity," wrote another. "Salute to Archana ma'am! You're really inspiration for all mothers," commented a third. Click for more trending news
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.