A Stamford police officer is on administrative leave following his arrest Wednesday on domestic violence charges.

Gregory Zach, 42, of Monroe, was arraigned in Stamford Superior Court Thursday on four counts of third-degree assault, one count of second-degree strangulation, two counts of second-degree threatening and three counts of disorderly conduct. According to Zach’s arrest warrant, the charges involve a woman he was dating and pertain to multiple incidents that took place from October of last year through June.

Stamford police began investigating one of their own after other officers heard rumors Zach was in a relationship with the woman and had recently spit on her “in front of numerous witnesses (who had now leaked this information),” the warrant said.

Officers decided to speak to her, and that’s when they learned of prior incidents of violence and intimidation, according to the warrant. She said the latest incident occurred June 26, but since then, Zach continues to show up at her house “unannounced and uninvited,” and sometimes while on-duty, the warrant stated. She also accused Zach of calling and texting her “incessantly.”

“At this point, I am very fearful of my safety regarding Greg Zach,” the woman told police, per the warrant.

Police were able to corroborate the allegations with photographs of the woman’s injuries and text messages between her and Zach, the warrant said.

In court, Judge Robert Golger issued a protective order barring Zach from any contact with the woman. Golger also ordered Zach to turn over all his firearms, including his police-issued weapon, which Zach said he'd already done. He’s to undergo substance abuse and mental health evaluations and treatment.

Zach joined the police department in 2005 and is now the subject of an internal investigation, according to Chief Timothy Shaw.

"The Stamford Police Department takes allegations of domestic violence very seriously and we will continue to work with and support the victim in this matter," Shaw said in a statement.

Zach has been investigated internally before. In 2009, a woman claimed he punched her in the face during an arrest downtown. Zach was suspended and put on probation after the department determined he used excessive force.

Zach is out on a $10,000 bond and due back in court Sept. 30.