A French left-wing Member of Parliament is calling on the government to shed light on the assassination of Burkina Faso president Thomas Sankara in a coup d'état 25 years ago.

Communist MP André Chassaigne says a commission of inquiry should investigate the coup that was then supported by Côte d'Ivoire, Liberia, Libya, the US and France.

Twelve Burkinabé MPs wrote to their French counterparts two years ago to demand a parliamentary inquiry into Sankara's death.

Chassaigne says it's time for France to heed their call.

"France, to an as-yet unknown extent, is responsible for this assassination," he said on Wednesday. "I believe that France, which today claims to behave differently towards Africa under what I personally would call a virtuous circle, must tell the truth.

"We cannot leave the people of Burkina Faso, and more broadly speaking, the peoples of Africa in the dark about what really happened."

An inquiry would be good for France, too, Chassaigne claims, adding that it would improve relations with African countries.