A senior Tisbury police officer, Sgt. Robert Fiske, has been placed on administrative leave by police chief Daniel Hanavan for the duration of an investigation of his conduct, town officials have confirmed.

Town administrator John Bugbee said yesterday that Sergeant Fiske had been on paid leave since Monday, August 1.

Neither he nor Chief Hanavan would speak about the details of the investigation.

But the action closely followed a July 23 incident which resulted in charges against David Thrift, 29, including the rape of a child under 16, assault with a dangerous weapon, the assault and battery of his wife, and violating an abuse prevention order.

According to the police report of the incident, Mr. Thrift’s wife called about 10:45 p.m. on July 23 to report that he had assaulted her at their home on West Spring street.

When police responded, they saw a shirtless man running from the house. They were told Mr. Thrift, his wife, their three young daughters and a 15-year-old babysitter had spent the day at the beach, where he had been drinking.

All had gone to bed when Mrs. Thrift was called to the teenager’s room, where she found her husband over the girl. He then assaulted his wife.

One of the three responding officers took Mrs. Thrift to the hospital for treatment, while Sergeant Fiske and the third officer searched for Mr. Thrift.

When they failed to find him, they returned to the station, leaving the children and babysitter in the house.

According to the statements given to police, Mr. Thrift later returned to the house and raped the teenager at knifepoint.

Mr. Thrift was found asleep at the house at about 12:43 a.m. and was arrested. He is being held without bail in the Edgartown house of correction.

When contacted yesterday, Chief Hanavan said he could not comment on whether the action to place Sergeant Fiske on leave was connected to his handling of the incident as the senior duty officer.

Mr. Bugbee said he hoped the investigation would be complete in another week or two.