Fifty-four years after it was sold by looters, an ancient Maya pictographic text has been judged authentic by scholars.

Doubts over whether the document – the oldest surviving pre-Hispanic document in the Americas – was kosher have circulated for decades because its design and style differs from that of other surviving scripts.

The document features pictures and symbols about the planet Venus.

But on Thursday, experts from Mexico's National Institute of History and Anthropology (NIHA) declared it the real thing following a series of tests.

“The Mayan Codex is authentic and the oldest, legible pre-Hispanic manuscript in the Americas,” said Diego Prieto Hernández, an anthropologist and head of the Mexican institute.