SAN JOSE — The San Jose Police Department has barred officers from working for the San Francisco 49ers after an officer who was moonlighting with team security complicated a domestic-violence investigation by going to defensive lineman Ray McDonald’s home the night he was arrested.

The decision was announced hours after this newspaper reported Sgt. Sean Pritchard, who was on duty and in uniform when he went to the McDonald home Aug. 31, also visited the home earlier that evening during a birthday party the player was throwing with his teammates.

“Due to the complexities of the investigation, both criminally and administratively, we feel that it is in our best interest to suspend all San Francisco 49er secondary employment related assignments until further notice,” Police Chief Larry Esquivel said in a brief statement released Friday afternoon.

The department declined any further comment. A 49ers spokesman also said Friday that the team would have no comment, and Pritchard could not be reached.

The development is the latest response by a department that faces tough questions about the relationship between the team and SJPD officers.

Earlier in the week, officials said they were reviewing how the department handles off-duty work by officers, but until Friday had allowed 16 other officers to continue to work for the team. Pritchard, a gang-suppression unit supervisor, had already been banned from such work, pending the results of an internal investigation.

Under scrutiny is what role Pritchard played in the Aug. 31 domestic-violence incident between McDonald and his pregnant fiancee that ended with the star defensive end’s arrest. Pritchard reportedly was called directly by McDonald that night and was already on scene when other officers arrived in response to a 911 call.

Internal Affairs

Pritchard was in uniform at the time, and questions about whether he was there on behalf of the department or the team has spurred an Internal Affairs probe. Police have not said when they will complete their overall review of secondary-employment policies, particularly with regard to conflicts of interest, which were mentioned in a 2012 city audit urging more oversight of officers’ off-duty work.

Peter Keane, a Golden Gate University School of Law professor and former San Francisco police commissioner, said he thought it was prudent for the department to take a step back.

“They need to make sure that the team isn’t hiring police officers to run interference for them with the law,” Keane said. “That would be very inappropriate if that were part of the job description. . . . If there’s an understanding that these officers are somehow going to be baby sitters, well that’s just not the proper role of police.”

Steven Clark, a former Santa Clara County prosecutor and now a criminal-defense attorney and legal analyst, agreed that Friday’s announcement could be an acknowledgment by the Police Department of the need for a serious review of the relationship between its officers and the team.

“I think they realize that the arrangement with the 49ers raises questions about what are the allegiances of its officers,” Clark said. “Instead of just singling out this one officer, I think they want to examine the overall protocols in these kinds of situations.”

He added it’s understandable that the department is concerned about whether officers are working for the team or the community at large.

“You never want a question like that to be raised,” Clark added. “That’s certainly not something that a DA’s office wants to deal with in a case.”

All of the SJPD officers were contracted through a third-party security firm to work for the NFL team.

Sources say Pritchard’s presence at McDonald’s house also stalled the investigation into the domestic-violence incident, where police said McDonald’s fiancee showed “visible injuries,” and was a factor in the case taking a month to be presented to the District Attorney’s Office. No charges have been filed and the case remains under review.

The new detail that Pritchard was at the birthday party a few hours before the arrest only fanned criticism that the arrangement has become too cozy to maintain the Police Department’s credibility in investigating players whose team employs its officers. The 49ers did not answer specific questions about its security arrangements but said in a general statement that it contracts security firms that hire off-duty and retired law enforcement to tap their expertise and experience.

Police brass also insist that the department’s ability to investigate the McDonald and other cases remains uncompromised, and that Pritchard, who was described as an “excellent officer,” should be afforded the benefit of the doubt until all the facts of the case are clear.

Contact Robert Salonga at 408-920-5002. Follow him at Twitter.com/robertsalonga.