Primo Leung (pictured), 36, who was charged with the sexual assault of a teen girl, was allowed to keep his job for three years prior to his arrest in April

A special education teacher, who was charged with the sexual assault of a teen girl, was allowed to keep his job for three years prior to his April arrest despite students reporting several incidences of inappropriate behavior.

Primo 'Howie' Leung, 36, of Concord, was taken into custody on April 3 while he was teaching at a high school in New Hampshire.

The Concord Police Department said it started investigating Leung in February.

Police allege that the married, father-of-two was in a sexual relationship with a former Rundlett Middle School student who said he abused her in 2015 and 2016.

During the time of the alleged abuse, Leung was working at a summer camp at the Fessenden School in Newton, Massachusetts. The Fessenden School fired Leung after his arrest.

'He would take students from up here, from Concord, to go down there and help him with their program,' Concord Police Lt Sean Ford said at the time.

'That's where some assaults did occur. A victim was exposed to inappropriate contact from him.'

Some the alleged behavior occurred while Leung was driving the victim home.

Several students had come forward to report behavior they deemed 'inappropriate' beginning in 2014. Leung (right, in court) was taken into custody on April 3

The Concord Police Department said it started investigating Leung in February. Police allege that Leung was in a sexual relationship with a former Rundlett Middle School (pictured) student who said he abused her in 2015 and 2016

During the time of the alleged abuse, Leung was working at a summer camp at the Fessenden School in Newton, Massachusetts. The Fessenden School (pictured) fired Leung after his arrest

It would involve him kissing her and placing her hand on his genitals over his clothes, according to prosecutor, Radu Brestyan.

A police affidavit said Leung was informed about the investigation on March 27.

Search warrants were executed at his home and at Concord High School.

On the next morning, according to the affidavit, police learned that Leung tried to kill himself.

Police took him to the hospital, where he remained until he was arrested.

'Right now, he enjoys the presumption of innocence,' said Leung's attorney, Jonathan Cohen.

'We've been provided no evidence in this case, so until that happens, we can't really address the accusations.'

In April, Concord School District Superintendent Terri Forsten said Leung was placed on paid administrative leave pending the outcome of the investigation.

'These allegations are despicable and sickening and are certainly not representative of the culture or the community that we work so hard to surround our students with here in the Concord School District,' she said in a letter to the school community.

Leung is facing two counts of aggravated rape of a child and one count indecent assault and battery on a child under the age of 14.

Leung (pictured) is facing two counts of aggravated rape of a child and one count indecent assault and battery on a child under the age of 14

On Monday, the Concord School Board faced questions about why Leung was allowed to stay on the job after students reported the inappropriate behavior.

Kate Frey told WCVB that her daughter, Ana Goble, was suspended for speaking up about Leung in middle school in 2014.

'It’s terrifying that the institutions we trust to care for our children are the very thing we need to protect them from,' Frey said.

Frey's daughter, Ana, told CBS in June that Leung 'would invite this special group of girls to lunches and field trips and he would kind of exclude other students and none of my other teachers at Rundlett would do that'.

Ana was then suspended for three days for reportedly 'spreading malicious and slanderous gossip'.

Parent, Darlene Gildersleeve, told WCVB that 'discouraging teens and children, especially children with disabilities, from coming forward, is absolutely reprehensible'.

The school board said on Monday that it will be launching its own independent investigation to determine what was done wrong.

A DailyMail.com request for comment to the school board was not immediately returned.