Both, the victim and the accused have been admitted to different hospital where their condition is said to be stable.
According to reports, the incident took place in a village under the Akbarpur Kotwali police station in Kanpur Dehat district on Saturday evening and the girl's father later lodged an FIR in the matter.
The girl's father, in his complaint, alleged that Yogendra had raped his minor daughter at gunpoint while she had gone to attend nature's call in the fields in the village outskirts.
After committing the rape, he allegedly poisoned the girl and later, he himself consumed the poison.
Meanwhile, some locals saw the girl and Yogendra frothing at the mouth and informed the police. The two were taken to the district hospital from where they were referred to Kanpur.
Amod Kumar, inspector Akbarpur Kotwali, said that preliminary investigations had revealed that the duo was in a relationship for a long time. However, their families were not in favour of their relationship.
On the complaint of the girl's father, an FIR has been registered under relevant sections of the IPC, including 376 (rape), 328 (causing hurt by means of poison etc with the intention to commit an offence) and the POCSO Act.
Police, however, are also working on the theory of a suicide pact between the two.
( With inputs from IANS )