Stephen "Greg" Fisk was found dead on Monday
, just weeks after taking office as the mayor of Alaska's capital, Juneau.
Juneau police told CNN at the time that Fisk had been discovered with injuries but that their cause was unclear.
Rumors the mayor had been the victim of an assault led police to issue a statement warning against speculation
On Wednesday, police spokesman Erann Kalwara said an autopsy had been conducted in Anchorage, with the preliminary report finding that no foul play was indicated in Fisk's death.
"According to the findings, the external injuries sustained by Mayor Fisk were consistent with an injury due to falling or stumbling into objects," Kalwara said in a statement
A final autopsy report, including toxicology results, was expected to be completed within about eight weeks, he said.
Police earlier said Fisk's son had found his father lying on the floor of a front room at the mayor's house.
When the son opened the door of his father's house, he started shouting, neighbors Don and Janet Kussart told the Juneau Empire newspaper. They said they didn't hear anything that sounded like an assault.
Juneau, population 32,000, is on Alaska's southeastern panhandle near Canada.
Fisk's first term as Juneau's mayor started in October and was scheduled to end in October 2018.
He was lauded for his positive campaign against incumbent Merrill Sanford, the Alaska Dispatch News reported.
Fisk had a background steeped in the fishing industry and was also working as a fisheries consultant, the Dispatch News said.