Konstantin Koltsov, the boyfriend of two-time tennis Grand Slam champion Aryna Sabalenka and a former ice hockey player, has died aged 42, the Belarusian hockey federation said on Tuesday.

In a short statement, the federation said that Koltsov "died suddenly", without saying how or where he died.

"We are in mourning," the federation said on its website.

"The Belarusian Hockey Federation expresses its deepest condolences to the family, friends, and everyone who knew and worked with Konstantin."

Koltsov's playing career included a stint with the Pittsburgh Penguins in the NHL.

There was no immediate reaction from the 25-year-old Sabalenka, the world number two, who is scheduled to play at the Miami Open this week.

The Belarusian won the Australian Open in 2023 and retained her Melbourne title earlier this year.