The Penang Education Department is probing the security company which hired the security guard who was involved in the murder of the Form Five student in the state on Sunday.

The department director Shaari Osman when contacted said the company has been asked to provide more information about the guard.

Shaari said the department will then submit a full report to the Education Ministry.

He said the ministry will take further action if it found the company guilty of going against the contract details between the ministry and the company in hiring the security guard.

In the incident on Sunday, Intan Suraya Mawardi, 17 was found with her throat slit by her father at her family's flat in Bandar Baru Teluk Kumbar.

Police have since detained a youth in his 20s, to assist in the investigation.

Penang CID chief Datuk Zakaria Ahmad told Bernama the victim was raped before she was murdered by her boyfriend, who works as a security guard at a school in Bayan Lepas.

Zakaria said the boyfriend who had a drug-related criminal record was detained in Teluk Kumbar about two hours after the student's body was found and he admitted to killing her.

He said the man also brought police to the place where he had discarded the knives which were used to kill the victim, in a hole nearby a substation by the school where he worked.