A husband and father of three who disappeared at a Wisconsin lake this summer may have faked his own death and fled to Eastern Europe, authorities say, and the sheriff is now urging the missing man to come forward to report.

“Our most important thing for us is knowing you are safe,” Green Lake County Sheriff Mark Podoll said in his message to Ryan Borgwardt. “We can discuss all this and figure it out together.”

The case began the morning of Aug. 12, when authorities learned that Borgwardt, 45, had not returned home and was last known to be on Green Lake, according to the Green Lake County Sheriff’s Office.

Borgwardt last texted his wife the night of Aug. 11, saying he was turning his kayak around and heading to shore soon, Podoll said.

Officials discovered Borgwardt’s overturned kayak and life jacket in the lake, authorities said, and later found his fishing pole and tackle box.

Rescuers believed the missing father had drowned and searched the lake using divers, drones, sonar and cadaver K-9s, officials said.

“The search lasted approximately 54 days, with no trace of Ryan,” the sheriff said during a news conference Friday. “Nearly daily drone searches were completed. And Bruce’s Legacy (a volunteer search organization) methodically searched approximately 1,500 acres. … Keith Cormican, (who heads) Bruce’s Legacy, searched hours and hours of sonar data and imagery.”

“Keith’s expertise and equipment led us to believe that something very strange had happened and that Ryan was outside the searched area, or that something else had happened,” the sheriff said.

The case took a turn in October when investigators discovered that Borgwardt’s name had been checked by law enforcement authorities in Canada on Aug. 13, the sheriff said.

Authorities also learned that Borgwardt had communicated with a woman from Uzbekistan, the sheriff said.

Other behavior included clearing his browsers the day he disappeared, asking about transferring money to foreign banks, getting a new life insurance policy, getting a new passport and replacing his laptop hard drive , the sheriff said.

“I was completely shocked,” Podoll told ABC News on Monday. “It was just unbelievable that we had to deal with a case like this, where a party had actually faked his death.”

Authorities have stopped searching the lake.

“As far as we know he is somewhere in Eastern Europe,” the sheriff told ABC News.

Investigators are “looking into what charges could be filed,” Podoll said, adding, “That’s a work in progress.”

Authorities are hoping for reimbursement for the costs of the search, the sheriff’s office said.

“He wasted a lot of my time and it cost me a lot of money,” said Cormican of Bruce’s Legacy.

Podoll said it is not clear whether Borgwardt has received help, and he urged anyone with information to come forward.

Podoll praised Borgwardt’s wife, who he said was not involved, calling her “a very, very strong lady.”

“I was there when the sheriff broke the news to the whole family. And it was pretty heartbreaking to see,” Cormican told ABC News. “I feel terrible for the family. They are the ones who are really going to have a hard time.”

ABC News’ Karolina Rivas contributed to this report.