Ryan Borgwardt of Watertown went missing on August 12 after going on a kayaking trip in Green Lake.
Crews recovered his capsized kayak, his car, a fishing pole, wallet, keys and his license.
The sheriff said they became suspicious after Borgwardt's name was checked by law enforcement one day after he disappeared.
"We don't know where he is, but he is not in our lake," said Green Lake Sheriff Mark Podoll said.
An investigation found Borgwardt had a second passport, replaced a hard drive on his laptop, cleared browsers on the day of his disappearance, had inquiries about moving funds to foreign banks, purchased airline gift cards, took out a $375,000 life insurance policy.
The sheriff's office also revealed he was communicating with a woman in Uzbekistan, a country in Central Asia.
Sheriff Podoll now asking the father of three to come back home to his family.
"It's really hard, because one, they felt that the dad was drowned a day ago. They found out that he wasn't," said Sheriff Podoll.
Bruce's Legacy, a nonprofit organization that specializes in water searches said they spent a lot of money searching for the missing husband.
"It's a little tough to swallow because it required a lot of expenses on this one," said founder Keith Cormican.
Cormican spent 23 days on the water, nearly half the time Borgwardt had been missing.
He was there when the Borgwardt family found out about the new developments.
"They were very shocked, as you can imagine, so very heart wrenching to the family," said Cormican.
The Green Lake Sheriff's Office will now work to identify any and all crimes committed and anyone who assisted with those crimes.
The sheriff said they will also pursue restitution for the expenses of the search that have been funded by taxpayers.
ABC News contributed to this report.
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