Police said the investigation into the death of an ice hockey player during a game is “likely to take some time”.
Adam Johnson of the Nottingham Panthers was fatally injured in the neck on Saturday night by a skate worn by Matt Petgrave of the Sheffield Steelers.
The 29-year-old man was taken to the hospital, where he was pronounced dead.
The Panthers invited people to attend a memorial event at their home stadium on Saturday.
South Yorkshire Police said they were investigating footage of the incident at Sheffield’s Utilita Arena.
A spokesperson said: “Since Saturday, detectives have been working to understand the circumstances of what happened, including reviewing footage, speaking to witnesses and requesting advice and assistance from highly specialized experts. We are conducting various investigations.”
“We are also working closely with Sheffield City Council’s health and safety department, who are assisting with the investigation.
“As with all sudden and unexpected deaths, it is standard practice for police to fully investigate the circumstances and feed the findings back to the coroner.
“Our officers have now left the scene, but due to the complex nature of this tragic and unprecedented incident, the extensive investigation may take some time.
“We will continue to investigate and provide updates as necessary and encourage the public to avoid speculation, including on social media.
“Our thoughts are with the loved ones of all those affected.”
Nottingham Panthers have announced that the Motorpoint Arena will open from 17:30 GMT on Saturday for a ‘gathering’ in memory of the player.
People will be invited to the ice, which will be carpeted, and sign a book of condolences.
Tributes continue to pour in for Johnson, a native of Minnesota.
Nottingham Panthers teammate Westin Michaud shared a photo of flowers, candles, photos and messages outside the arena, writing: “Outpouring of love and support.
“My team and family would like to sincerely thank you all.”
A vigil was held Monday night at the game between the Pittsburgh Penguins (where Johnson previously played) and the Anaheim Ducks at PPG Paints Arena.
Before the game, members of both teams lined up on the ice, and the crowd cheered in memory of Johnson.
Pittsburgh Penguins players also wore the “AJ 47” label on their helmets.
“It’s an unbelievable tragedy,” Penguins coach Mike Sullivan said. “He was a great kid. It was an honor to coach him…I remember his first game and his first goal in Minnesota. “I’m working on it,” he said.
“He was a great kid, a great player. And he could really skate.”