Public prosecutors in Brazil have called for the suspension of work on the Rio 2016 Olympic golf course over environmental concerns.
The move casts fresh doubt over the planning for the Games, just weeks after International Olympic Committee vice-president John Coates described preparations for the event as the "worst he had seen".
According to Rio prosecutors, the project breaches laws that protect the site, Reserva de Marapendi in Barra de Tijuca, located on the heritage-listed Atlantic rainforest.
The Ministry called for work to be halted until a new environmental study was concluded.
Earlier this month, Rio 2016 officials had claimed the troubled project was back on track after the grass-planting process on one of the 18 holes begun on the course designed by Gil Hanse.
In March International Golf Federation President Peter Dawson claimed he was confident the venue will be ready for the Games itself but remains "dissatisfied" with the slow progress which means the chances of a test event being held before the sport returns to the Olympics after a 116-year absence are slim.
Construction was originally due to begin on the course in October 2012 but, following a legal dispute over the ownership of the land between Italian developer Mauro Pasquale and Elmway Participacoes, it was not given the green light until April 2013.
Rio 2016 spokesman Mario Andrada confirmed the inquiry and said developers had been asked to provide documentation that would allow the work to continue.
They have ten days to produce the documents, according to Brazilian law.
''The State prosecutor is asking for the papers to show the work is proceeding according to the law,'' Andrada said.
''We believe all the rules are being followed.''
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May 2014: Grass-planting at Olympic golf course begins amid delay concerns
May 2014: Rio 2016 golf test event one year out from Games improbable, admits IGF vice-president Votaw
March 2014: Fear Rio 2016 will not be ready to host test golf event because so far behind in preparations
June 2013: Bird's-eye view pictures of Rio 2016 Olympic golf course released
April 2013: Construction of Rio 2016 golf course finally gets green light