A Wisconsin man who faked his own drowning death in August and fled to Eastern Europe is in police custody after several months, the authorities said on Wednesday.

Ryan Borgwardt, of Watertown, Wis., returned to the United States on his own on Tuesday, according to the Green Lake County Sheriff’s Office. Sheriff Mark A. Podoll said on Wednesday that Mr. Borgwardt, 45, had flown back from an undisclosed country and had been booked in the county jail. He has not yet been charged with a crime.

“He came back on his own,” Sheriff Podoll said at a news conference Wednesday morning.

Mr. Borgwardt’s return brought an end to a monthslong saga that included an intensive search involving divers, and became an international missing-persons case that involved a number of federal agencies.

In August, Mr. Borgwardt, 45, made it appear as though he had drowned while fishing in Green Lake, about 65 miles southwest of Green Bay, leaving behind a capsized kayak and his vehicle, Sheriff Podoll said. Investigators also found Mr. Borgwardt’s fishing rod and a tackle box with his keys, wallet and driver’s license inside.

The authorities spent weeks searching the lake for his body before a digital forensic analysis of a laptop his wife had given to investigators revealed that Mr. Borgwardt had moved money into a foreign bank account and had been communicating with a woman in Uzbekistan, Sheriff Podoll said, leading the authorities to believe that he had fled the country.

Data on the laptop also showed that he had bought an airline gift card and had taken out a $375,000 life insurance policy to benefit his family, Sheriff Podoll said.

This is a developing story.