There was a loud applause from the public gallery after the verdicts were read out and Mr Mear thanked the jury before leaving the dock and hugging his wife.
Outside court, Mr Mear and his wife cried and hugged their supporters.
He declined to comment.
In his closing address, defence lawyer Paul Mabey QC had said Mr Collier did not deserve the treatment he got at the hands of the Rotorua police but Mear was innocent.
Mr Mabey criticised the length of time it took for police to launch an investigation, the "inadequate" paperwork by senior police officers and the lack of forensic evidence.
"The investigation was inadequate... You do not make a decision on the innocence or guilt with information that shabby."
Mr Mear has been suspended on full pay since the start of the investigation late 2010. It was not immediately clear if or when he would rejoin the force.