The victim, identified as Oluwakemi in a Punch report, was reportedly found foaming in the mouth on Sunday.
Oluwakemi was rushed to a hospital where she died.
Reports say the deceased was a student at a polytechnic in Oyo state and was in Mowe to attend a church convention.
She had stayed in the town for two weeks with a friends before leaving for Lagos to visit her brother-in-law on Saturday, returning the same day.
Later that day, she began to complain of headache and was unable to attend church service Sunday only to be found foaming in the mouth in the afternoon.
She was rushed to the Redeemed Health Centre, Mowe, where she died.
Some resident, like Mama Afeez who spoke to Punch, believe that the deceased was poisoned.
“It was when she came back that she started complaining about stomach upset and headache," Mama Afeez said.
The Ogun State Police Public Relations Officer, DSP Muyiwa Adejobi, said Oluwakemi's death has been ruled as sudden death because no foul play is suspected.
“The case was reported, but the police are not investigating anything because no foul play was suspected," he told Punch.
He added that the family had already taken her corpse for burial.