The tournament was to feature Newcastle, SuperSport United, Orlando Pirates and Kaizer Chiefs staged in Durban, a port city on the country’s east coast.
The competition was won by Tottenham Hotspur last year and has been running since 1999.
Newcastle today declined to comment on speculation that the tournament has been cancelled.
The club will face Olympiacos and FC Porto in the Guadiana Torneo on the Algarve, Portugal, late next month.
Newcastle take on Olympiacos on July 27, and FC Porto 24 hours later.
And United will also visit Championship club Cardiff City on August 11.