Amina Raphael Mbunda, 26, was arrested at her home in the eastern district of Kilombero on the evening of June 2 by officers searching for her husband whom they suspected of having bought a stolen bed, local media reported.
Heavily pregnant, Mbunda asked to be taken to hospital but her request was refused, according to the Mwananchi daily newspaper.
She eventually gave birth on the front lawn of the police station in the middle of the night.
The affair was confirmed by the regional police commander, who said an investigation had been opened.
Tanzanian rights groups were outraged at Mbunda’s alleged treatment.
“Shame on the police force,” Helen Kijo-Bisimba, head of Tanzania’s Legal and Human Rights Centre, said on Twitter.
“How can someone be arrested for a penal infraction committed by someone else? And how come they didn’t realise she was about to give birth? What would have happened if she’d died in that police station?”
The Coalition Against Violence Against Women and Children issued a statement condemning how the woman’s life was endangered.
“This incident adds to the list of people subjected to cruelty and humiliation inflicted by the police.”