A man has been arrested in Florida on suspicion of killing his wife and three children — deaths that were discovered only when federal agents tried to arrest him in a separate investigation, authorities said.

Anthony Todt, 44, initially was detained Monday at his rented home in Celebration — a community adjacent to Disney World — as agents with the Department of Health and Human Services and sheriff’s deputies arrived to serve a federal arrest warrant, Osceola County Sheriff Russell Gibson said Wednesday.

Deputies checking the home then found four bodies, which investigators believe are those of his wife, Megan Todt, 42, and their three children, ages 4, 11 and 13, Gibson said. Authorities said they will need to use DNA or dental records to confirm identities.

It was not clear whether Todt has an attorney. He has an initial court appearance set for Thursday.

Todt’s sister, Chrissy Caplet, released a statement: “Tony and Megan were devoted loving parents who loved their children and Breezy every day and were so involved in their community. The families of Tony and Megan ask for privacy during this difficult time in our lives as we mourn the lose [sic] of our families.”

Todt worked in Connecticut but spent weekends at that Florida home, where his family lived. He told investigators he killed the four — and the family dog, according to Gibson.

Based on statements they received from Todt, authorities believe the family members were killed sometime at the end of December, authorities said.

Gibson said he didn’t immediately know why Todt allegedly killed his family and the dog, and he declined to say how they were killed, saying a medical examiner has yet to make a final ruling.

Gibson said he didn’t know why federal agents were investigating Todt. It was related to “something that was occurring up there in Connecticut,” where he worked as a physical therapist, the sheriff said.

The Connecticut attorney general’s office told CNN it was investigating Todt for potential violation of the False Claims Act, but did not elaborate. The office didn’t say whether it meant the federal act or a similar state law, both of which prohibit people from making a fraudulent claim for government payment.

Todt was taken to a hospital after telling the officers Monday he took some pills. The hospital eventually released him, and he was arrested Wednesday on suspicion of homicide and animal cruelty, Gibson said.

A relative asked for a well-being check on December 29

Deputies had been at the Florida home several times before the killings were discovered — starting with a well-being check that one of Todt’s out-of-state relatives requested late last month, Gibson said.

The relative contacted the sheriff’s office on December 29 “because she had been told that (the Todt family) all had the flu and she had not heard from them in two days,” Gibson said.

A deputy went to the home, but no one answered the door. The deputy did not enter the house, because he or she had no cause to do so, the sheriff said.

“The deputy walked around the house, checked with neighbors. The blinds of the home was closed. Nothing suspicious was noted, and therefore they didn’t enter the home,” Gibson said.

In hindsight, it is possible that the killings had happened by then, the sheriff said.

Deputies returned to the home January 9, this time because federal agents had told the sheriff’s office that Todt was under investigation, Gibson said.

“Deputies from that point made several attempts to make contact with Anthony and the family over this past weekend,” but didn’t find Todt there until Monday, Gibson said.

A neighbor, Michelle Augustin, told CNN affiliate WFTV that she hadn’t seen the Todt family since November, and that the family’s landlord was outside the house, looking for them, on Friday.

“My mom …saw over (on) the property that somebody was looking into the windows,” she told WFTV. “He had already cut off the electricity — the owner — because the renter hadn’t paid.”