VIDEO SHOWS: MESSAGES POSTED ON TWITTER PAGES OF ROGER FEDERER, RAFA NADAL, NOVAK DJOKOVIC, NAOMI OSAKA AND COCO GAUFF, FILE FOOTAGE OF ROGER FEDERER, NOVAK DJOKOVIC, RAFA NADAL, NAOMI OSAKA AND COCO GAUFF SHOWS: INTERNET (JUNE 2, 2020) (SOCIAL MEDIA WEBSITE - ACCESS ALL) (MUTE) 1.

POST ON ROGER FEDERER'S TWITTER PAGE SHOWING A HEART EMOJI AND A BLACK SQUARE AS PART OF THE #BLACKOUTTUESDAY CAMPAIGN 2.

POST ON RAFA NADAL'S TWITTER PAGE SHOWING A BLACK SQUARE AS PART OF THE #BLACKOUTTUESDAY CAMPAIGN 3.

POST ON NOVAK DJOKOVIC'S TWITTER PAGE WITH MESSAGE, READING: "BLACK LIVES MATTER #BLACKOUTTUESDAY" AND A BLACK SQUARE AS PART OF THE #BLACKOUTTUESDAY CAMPAIGN 4.

POST ON NAOMI OSAKA'S TWITTER PAGE READING: "THIS.

IF YOU HAVEN'T SPOKEN OUT AT ALL DURING THIS LAST WEEK ASK YOURSELF WHY.

IF YOU FEEL UNCOMFORTABLE USING YOUR PLATFORM TO STAND UP FOR JUSTICE ASK YOURSELF WHY.

IF YOU FEEL COMFORTABLE POSTING ABOUT THE WOMEN'S MARCH, THE CLIMATE MARCH, BUT NOT ABOUT JUSTICE FOR BLACK LIVES ASK YOURSELF WHY" 5.

POST ON COCO GAUFF'S TWITTER PAGE WITH MESSAGE, READING: "#BLACKOUTTUESDAY" AND A BLACK SQUARE AS PART OF THE #BLACKOUTTUESDAY CAMPAIGN LONDON, ENGLAND, UNITED KINGDOM (FILE - NOVEMBER 8, 2019) (REUTERS - ACCESS ALL) 6.

NOVAK DJOKOVIC PRACTISING 7.

ROGER FEDERER PRACTISING 8.

RAFAEL NADAL PRACTISING SINGAPORE (FILE - OCTOBER 20, 2018) (REUTERS - ACCESS ALL) 9.

VARIOUS OF NAOMI OSAKA PRACTISING AHEAD OF THE WTA FINALS WASHINGTON, D.C., UNITED STATES (FILE - JULY 26, 2019) (REUTERS - ACCESS ALL) 10.

VARIOUS OF COCO GAUFF PRACTISING STORY: Roger Federer, Rafa Nadal and Novak Djokovic were among the tennis players who joined the #BlackOutTuesday campaign against racial injustice, as protests continue over the death of George Floyd, an unarmed black man who died in police custody.

Floyd died after a white policeman pinned his neck under a knee for nearly nine minutes in Minneapolis on May 25.

Men's world No.

1 Djokovic posted black screenshots on his Twitter and Instagram pages with the message "Black Lives Matter", and was joined by Federer and Nadal, the other members of the "Big Three" of men's tennis.

Grand Slam winners Maria Sharapova, Petra Kvitova and Stan Wawrinka were among other players who signalled their support for the campaign.

African-American teenage phenomenon Coco Gauff and Japan's Naomi Osaka have also expressed their anger over Floyd's death.

Replying to Federer's Instagram post, the 16-year-old Gauff commented: "Click the link in my bio to get resources on HOW YOU CAN HELP!

THANK YOU." Osaka, whose father is Haitian and mother is Japanese, said people should be doing more than posting "the black square".

(Production: Tim Hart)