Ekeng fell to the floor in the 70th minute of a televised Romanian league match between Dinamo and Viitorul.
He was pronounced dead in hospital two hours later.
The Cameroonian FA confirmed the news on Twitter, while Ekeng’s former club Cordoba tweeted: “We have no words to express our sadness at the loss.”
Ekeng had also previously played for Le Mans and Lausanne.
In 2003, Cameroon international midfielder Marc-Vivien Foe died after collapsing during a Confederations Cup match against Colombia in France