Local media reported the little girl was found naked in the officer’s quarters in the northern state of Uttar Pradesh.
Police Superintendent Vipin Tada told AFP: “We sent her for a medical examination and are awaiting a final report.
“The policeman will be undergoing medical tests to confirm whether he was consuming alcohol inside his quarters.”
The Press Trust of India reported that angry locals tried to attack the local police in protest, but were apparently pacified when they learned the suspect had been arrested.
India has an endemic problem with sexual assaults against children, with more than 10,000 cases reported in 2015, according to government statistics – with convictions in only a few dozen such cases.
Despite strengthening its laws on sexual violence after the fatal gang-rape of a 23-year-old medical student in Delhi in 2012 caused global outrage, rape against women and children remain commonplace in the country.
There have also been reports of Indian doctors being afraid to help child rape victims obtain abortions for fear of criminal prosecution.
Delhi’s Commissioner for Women, Swati Maliwal, has called for better policing to help bring the perpetrators to justice – but has also pointed out that poverty appears to be a major factor in rape and incest cases.