The Ivorian enforcer spent seven years on Tyneside, becoming a fan favourite thanks to his combative style of play.
In February, he joined Chinese League One side Beijing Enterprises for an undisclosed fee, making 11 appearances for the club.
But shock rumours circulating on social media claim the 30-year-old collapsed during a session at the club’s training ground.
There are unconfirmed reports that he has been taken to hospital prompting fears over his health.
In 2014, Bolton midfielder Fabrice Muamba collapsed and was revived on the pitch after his heart stopped for 78 minutes during a fixture against Bolton Wanderers.
And earlier this year, Tottenham youth coach and former England star Ugo Ehiogu collapsed at the club’s training ground.
The 44-year-old later passed away of a suspected cardiac arrest.
His most iconic moment in a black-and-white shirt came during Newcastle’s memorable 4-4 draw at St James’ Park, when the home side fought back from 4-0 down at half-time to earn a point.
Tiote scored the only goal of his Newcastle career during that game with a left-footed volley from 25 yards in the 87th minute to seal the result.
Former teammate Demba Ba paid tribute to his friend, tweeting: “May Allah gives grant you Jannah, brother Tiote.”
Toon supporters have been left distraught by the rumours.
“Heartbreaking if true. Far too young to have gone. Praying it’s not,” said one fan.