The Safety Investigation Authority (SIA) has begun a preliminary investigation of a deadly collision at a major boating event in Hanko on Saturday.
SIA announced the probe via Twitter on Saturday evening following the death of one of the two people injured in the crash.
On Sunday police said that the deceased was a child of primary school age. They said the incident was being investigated as a case of suspected manslaughter, grievous bodily injury and endangerment of traffic.
A racing boat and a yacht collided on Saturday near the coast of Hanko. One person was on the speedboat and four were on the yacht. The deceased and the injured person were both on the yacht.
Raceboat was "going at high speed"
The accident took place during the 15th annual Poker Run, billed as Finland's biggest powerboat event.
The rest of the three-day event was cancelled after the crash.
SIA director Veli-Pekka Nurmi told Yle that the raceboat had been going at high speed.
He said that besides the boaters' actions, the safety watchdog is looking into how the event organisers had arranged spectator areas on the water and on land.
Nurmi noted that similar accidents involving competitors and spectators have occurred before, primarily at motor sport events.
40 high-speed 'muscle boats'
The Poker Run is not a race but a mass boating procession between Hanko and Kasnäs, a port in the municipality of Kimitoön on the southwest coast. Hanko, mainland Finland's southernmost town, is a major resort and port city.
A year ago, two people were killed when a speedboat struck a sailboat in Airisto, also on the southwest coast.
On Thursday the event's communications director, Petri Järvinen, told Yle that some 40 boats were to take part. He said all the participating vessels are high-performance 'muscle boats' with a top speed of over 40 knots (74 km per hour), describing them as "Miami Vice style power boats".
He said they included Finland's fastest boat, which has been clocked at 137 knots, or nearly 250 kph.
9.8: Updated with police statements on Sunday and photo.