A southern New Jersey teacher who oversees a classroom where a father says his autistic son was verbally abused by adults has been placed on paid leave, according to district officials. The father, Stuart Chaifetz, posted clips on YouTube days ago of secretly recorded audio that caught one adult calling his autistic 10-year-old son "a bastard." A lawyer for the teacher, Kelly Altenburg, has denied that she was in the classroom when the abusive remarks were made and said an investigation by the district also found that Altenburg was not present. Officials say one school aide resigned, another was put on leave and a substitute aide was not invited back amid the allegations. Cherry Hill Superintendent Maureen Reusche said she put Altenburg on leave to minimize the "disruption to our schools." Speaking at a news conference Friday, lawyer Matthew Wieliczko said Altenburg is a dedicated special education teacher of 23 years who did not know about the comments until she was contacted by district officials about the covert recording and after Chaifetz posted his first recording. Altenburg does not condone the comments, they said. In cases around the country, suspicious parents have been taking advantage of convenient, inexpensive technology to tell them what children, because of their disabilities, are not able to express on their own. The practice can help expose abuses, but some experts say it could violate the rights of other children. Chaifetz has said he sent his son Akian into school wearing a recording device stashed in his pocket. The father said the tape revealed teachers at the school chiding and mocking Akian in a class that contains only children with autism who have trouble communicating. Chaifetz took the step after getting reports earlier in the school year that his son was being violent. Hitting teachers and throwing chairs were out of character for the boy, who speaks but has serious difficulty expressing himself. Chaifetz said he talked to school officials and had his son meet with a behaviorist. There was no explanation for the way Akian was acting. "I just knew I had to find out what was happening there," he said. My only option was to put a recorder there. I needed to hear what a normal day was like in there.