"It was an accident due to an electrical short circuit," Dubai police chief Khamis al-Muzainah told reporters.
"No one was arrested. There is no suspicion of a crime... There was no negligence," he said.
The fire broke out at the 63-storey The Address Downtown hotel on December 31, a few hours before Dubai welcomed 2016 with a fireworks display from the iconic Burj Khalifa, the world's tallest tower, a few blocks away.
The hotel was evacuated and 16 people suffered minor injuries.