NEWARK — With his colleagues looking on, an Essex County Sheriff's officer pleaded not guilty on Wednesday to charges of sexually assaulting a prostitute in February after threatening to arrest her.

Wearing a gray suit, Dinis Oliveira, 31, of Newark, appeared with his attorney before Municipal Court Judge Marilyn Williams for his arraignment on charges of sexual assault, official misconduct and criminal coercion. Three members of the sheriff's department attended the hearing.

Outside the courtroom afterwards, his attorney, Charles Sciarra, said Oliveira "absolutely denies" committing the alleged offenses.

"He denies every aspect of the allegations against him," Sciarra said.

Oliveira is scheduled to return to court on May 4 for an appearance before Superior Court Judge Peter Ryan.

Law enforcement sources have said Oliveira contacted the 31-year-old Newark woman by phone after seeing an advertisement posted on Backpage.com, and arranged a meeting with her.

During their Feb. 26 encounter, Oliveira used both his badge and a handgun to intimidate the woman, and they then engaged in both oral and vaginal sex, according to a criminal complaint filed in Essex County Superior Court.

The woman reported the alleged assault to authorities two days later.

She also presented authorities with a condom she claimed Oliveira used during the assault, and was taken to Newark Beth Israel Hospital to be examined, sources have said. At the hospital, the woman spotted Oliveira, who was there assisting a family member, and she alerted police.

Oliveira turned himself into the Essex County Prosecutor's Office and briefly remained in custody before posting $200,000 bail. Oliveira, who has been a sheriff's officer since June, has been suspended without pay pending the outcome of his case.

But Sciarra challenged the information provided by prosecutors and questioned why the woman waited two days to report the alleged incident.

"On just the six pages of information we've been given already there are glaring inconsistencies. Why wait two days to report the alleged incident? The time lines don't comport," Sciarra said in an email after Wednesday's hearing. "Even the occupation listed for the alleged victim differs with the prosecutor's account. Dinis will fight to be vindicated."

The Essex County Prosecutor's Office declined to respond to Sciarra's comments.

During Wednesday's hearing, Williams maintained Oliveira's bail and ordered him to have no contact with the alleged victim.

Since the woman lives in the same Newark neigborhood as Oliveira, the judge said he could not live at his address. If Oliveira wants to retrieve clothing from his home, Williams said he would need a police escort.

Oliveira indicated he would reside at an address in Union Township, Union County.

Sciarra noted during the hearing that Oliveira's church is located around the corner from his Newark address. The judge said Oliveira could attend the church as long as he stays away from the alleged victim.

Referring to the church, Williams said that "as long as she's not there, it's not a problem."

Reporter Dan Ivers contributed to this report.

Bill Wichert may be reached at bwichert@njadvancemedia.com. Follow him on Twitter @BillWichertNJ. Find NJ.com on Facebook.