MEXICO CITY (AFP) .- Iconic 20th-century artist Frida Kahlo has one of the best-known faces on the planet, but the world at large has never heard the Mexican painter's voice -- until, possibly, now.



Kahlo, who is instantly recognizable with her convention-defying unibrow, spent her life as a painter in the daunting artistic shadow of her husband, the muralist Diego Rivera.



And while there are many silent films of her, the Mexican culture ministry says there are no known audio recordings.



But one may just have been found in the private collection of a legendary host from Mexico's "golden age of radio" in the 1950s, it says.



"Frida's voice has always been a great enigma, a never-ending search," the head of the national audio archives, Pavel Granados, told a press conference at which the ministry unveiled the newly discovered recording.



"Until now, there had never been a recording of Frida Kahlo," he added.



The tape was found in the archives of late radio personality Alvaro "The Bachelor" Galvez y Fuentes.



On it, a woman with a soft, melodious voice reads a text that Kahlo (1907-1954) wrote about Rivera in 1949, celebrating the 50th anniversary of his artistic career.



"He is a gigantic, immense child, with a friendly face and a sad gaze," she says after an introductory trickle of guitar.



"His high, dark, extremely intelligent and big eyes rarely hold still. They almost come out of their sockets because of their swollen and protuberant eyelids -- like a toad's. They allow his gaze to take in a much wider visual field, as if they were built especially for a painter of large spaces and crowds."



Galvez y Fuentes acquired the recording for a radio program he hosted in 1956 on Rivera (1886-1957), the culture ministry said.



Experts are analyzing it in hopes of determining with certainty whether it is Kahlo.



What they have established so far is that the audio was made with external recording equipment, not in a studio, said Granados.



The voice seems to match French photographer Gisele Freund's description of Kahlo's: "Frida smokes, laughs, speaks with a warm and melodious voice," she once wrote.



Culture Minister Alejandra Frausto said specialists continue analyzing Galvez y Fuentes's collection and consulting other sources that could confirm whether the voice in the recording belongs to "Frida, one of the most iconic cultural personalities there is."





© Agence France-Presse