A TEMPLE built 1600 years ago to honour a Mayan king by streaming sunlight around his tomb is being excavated in the dense forests of Guatemala.

"The sun was a key element of Maya rulership," lead archeologist Stephen Houston explained in announcing the discovery by the joint Guatemalan and American team that has been excavating the El Zotz site since 2006.

"It's something that rises every day and penetrates into all nooks and crannies, just as royal power presumably would," said Houston, a professor at Brown University, Rhode Island.

"This building is one that celebrates this close linkage between the king and this most powerful and dominant of celestial presences."

Archeologists say the temple was likely built to honour the leader buried under the Diablo Pyramid tomb, the governor and founder of the first El Zotz dynasty called Pa'Chan, or "fortified sky."

Mayan civilisation, which spread through southern Mexico, Guatemala, Honduras, El Salvador, and Belize, was at its height between 250 and 900 AD.

Carbon dating places construction of the temple at the early part of that era, somewhere between 350 and 400 AD, the archeologists said.

It is ornately decorated with massive stucco masks, 1.5 meters tall, each depicting the phases of the sun as it moves east to west, and a painted stucco frieze that the team described as "incredible."

More than half the temple is still to be excavated, co-project leader Thomas Garrison of the University of Southern California told a press conference on Wednesday at Guatemala City's National Palace of Culture.

"The temple probably had 14 masks at the height of the frieze, but only eight of them have been documented" so far, which is why excavations must continue, added University of Austin archeologist Edwin Roman.

Excavations by the Guatemalan and American team began at the El Zotz dig in 2006, but the temple wasn't uncovered until three years ago.

Originally published as Sun-king temple emerges from forest