ARTICLE AD BOX
By Vanessa Buschschlüter
BBC News
A judge in Mexico has delivered a fresh blow to the Maya train project, which aims to link archaeological sites with Mexican beach resorts.
The judge ordered that a suspension of construction work on a stretch of the train line be extended until its environmental impact is determined.
The ruling is a victory for a group of cave divers who fear that the works will threaten underground caverns.
The Maya train is one of Mexico's most ambitious infrastructure projects.
This latest ruling could halt building work by months or even years unless an appeal by the authority behind the project is successful.
The $9.8bn (£7.5bn) Maya train project is aimed at building a 1,500km-long (930-mile) railroad linking the south-eastern Mexican states of Chiapas, Tabasco, Campeche, Yucatán and Quintana Roo.
President Andrés Manuel López Obrador argues that it will provide an environmentally friendly mode of transport for locals and tourists alike, as well as boosting development and employment in the underdeveloped region.
But critics say the megaproject has been rushed and environmental concerns have been overridden.
The current legal battle centres on a particular stretch of the railroad, known as Section 5, which links the tourist hotspots of Cancún and Tulum.
The controversy arose after the route was changed to run through an area of jungle which is rich in ancient underground caves.
Environmentalists and speleologists warned that the heavy machinery used to build the railroad would irreparably damage the unique cave system.
On Monday, the same judge declared the suspension "definite", ordering that no works be carried out on this particular stretch until environmental impact studies have not just been carried out but also approved according to Mexican law.
The judge said that he was acting to "prevent imminent and irreparable damages to the environment".