The Australian Open champion suffered a surprise 0-6 6-4 6-4 loss to unseeded Puerto Rican Monica Puig on Friday.

Afterwards the 27-year-old Dane revealed her parents were subjected to death threats and young members of her family were sworn at.

She wrote on Twitter: “During the match last night people in the crowd threatened my family, wished death upon my mom and dad, called me names that I can’t repeat here and told my fiance’s niece and nephew (who are 10 years old) to sit down and shut the f*** up.

“Meanwhile security and staff did nothing to prevent this and even accepted this to take place.

“While I always encourage fans to cheer for their favourite player, and I thrive on a challenging atmosphere, when certain lines are crossed it makes tennis miserable for both competitors.”

Wozniacki called on Miami Open bosses to take action in a bid to prevent a repeat.

She added: “I hope the Miami Open chooses to take this seriously because it’s a horrible example to set for the next generation of tennis players and fans.”

Puig, 24, faces Maria Sakkari of Greece in the third round.