RIO DE JANEIRO -- In a move to protect a nature reserve, a Brazilian court has proposed changes that throw into question the future of the golf course being built for the 2016 Olympics.

The course developer and the city of Rio de Janeiro, both defendants in a lawsuit brought by a public prosecutor, have until Sept. 17 to say if they will make changes to the layout proposed by the court and Rio Judge Eduardo Klausner.

If not, it's unclear where golf will be played in the 2016 Olympics when it returns after a 112-year absence.

The course is being carved out of an environmentally protected area -- some of the city's last green space and most valuable real estate -- and was approved by Rio's city government in a legal move that's being questioned.

The golf project has been in dispute since plans to build the course began almost five years ago.

Public prosecutor Marcus Leal, arguing before Judge Klausner on Wednesday, said questions of ownership and environmental problems surrounding the course were well known.

"This is not a surprise," he said.

The court's proposal, which allows construction to continue but no new ground to be broken, seems to have caught many flat-footed.

Some have questioned the need to build a new course for the Olympics. At least one other venue in the Rio area, the Itanhanga Golf Club, might have been suitable. It has hosted the European Tour, and a U.S. LPGA Tour event.

Ty Votaw, vice president of golf world governing body the IGF, tried to find a bright light.

"Construction continuing is something we see as a positive," he told The Associated Press on Thursday. He said sod and grass had been laid over the last few months and the course was being irrigated.

He said little else.

There was no immediate reply to requests by AP for comment from the city of Rio and the golf course architect Gil Hanse. Rio's local organizing committee also declined to comment after a short statement on Wednesday.

Under the judge's proposal, the golf course layout would need to move away from a lagoon on its south side and toward a multi-lane highway on the north. By shifting the course northward to make room for a 400-meter-wide green corridor, some of the course would have to be built on land zoned for the construction of high-end apartments selling for between $2.5-7 million.

A key developer in the project is Pasquale Mauro, one of the largest landowners in the Barra da Tijuca area of suburban Rio where many of the Olympic venues will be located.

"It is in society's interests that the Olympics take place and it's also in society's interests that the environment be preserved," the judge said. "What has to be observed is legality, and within legality is respect for the environment."