Nguyen Viet Anh, 36, will be investigated for the crime of "engaging in sexual intercourse or other sexual activities with a person aged 13 to under 16."

His crime came to light after the girl’s family filed a complaint with the local police Monday, saying that she was 12 weeks pregnant.   

Anh has reportedly confessed to the police that he had sex with the girl on multiple occasions at the school since late 2017. The victim was a seventh-grade student then.

According to the victim’s family, he had bought her a cell phone to contact her. They only came to know of the relationship after noticing some abnormal signs in her and taking her to hospital, where they discovered she was pregnant.

Police will carry out a DNA test to identify the father of the child before taking further steps.  

Having sex with a child under 13 years of age in Vietnam is ruled as rape, and is punishable by between 12 years in prison and death. Having sex with a child between 13 and 16 years old faces up to 15 years in jail.

This is not the first time a Vietnamese teacher has been involved in sexual abuse of their students.

A court in Da Nang City last month sentenced Nguyen Quang Chung, a former primary school teacher, to life imprisonment for raping several third-grade girls.

Last December, the principal of a boarding school in Phu Tho Province was arrested for molesting many boys at the school over the period of several years.

According to official reports, approximately one in four children in Vietnam is a victim of sex abuse and at least 1,300 cases of sexual violence against children are reported each year. The perpetrators are usually those close to the children or having authority over them.

Vietnam recorded 1,547 child sex abuse cases in 2018, down 2.8 percent from a year ago, according to the Ministry of Public Security.