The government says it has identified 486 victims of the earthquake and tidal wave, but that figure could rise because 79 people are still listed as missing.
The police report concluded that about 100 people died from drowning, while others suffered heart attacks and blunt trauma, but it did not say how many of these deaths were due to the tidal wave.
The document will be submitted this week to the interior ministry and to prosecutor Solange Huerta, who is investigating possible criminal liability related to officials' failure to issue timely tsunami warnings.
Victims' relatives have filed lawsuits against officials in connection with the failure to warn the public about the tidal wave after the earthquake, which affected 800,000 people and caused $30 billion in damages.