KOPPAL: A 15-year-old girl student of a government school was allegedly raped by her guardian for the past several months following which she became pregnant, police said on Wednesday.Krishnappa, who works as a labourer in Basrikatte village of Karnataka 's Koppal district, along with his blind wife Shanthamma took custody of minor girl after she was abandoned by her biological parents."Krishnappa, who is a drunkard, allegedly assaulted and raped the victim on several occasions. He had also threatened the victim of serious consequences if she complained about it," a senior police official said, adding that the girl is studying in class 7 in a local government school.It was only after the minor girl became pregnant, villagers approached the police and the investigations have been started, police said."Krishnappa is a serial offender. He was earlier arrested for running an illegal slaughter house near his house," the police official said.