Rio the 'most perfect imperfect Games' - IOC

"Everything worked" during the Games in Rio de Janeiro earlier this year, the International Olympic Committee said Tuesday, insisting the event was the best it could be under difficult circumstances.

"Someone called them the most perfect imperfect Games, it's actually quite a good characterisation," IOC spokesman Mark Adams told reporters in Lausanne.

Preparations for the 2016 Games were marred by massive political and economic crises rocking Brazil and organisers were embarrassed by low attendances and problems with transportation, crime and water pollution.

Considering the challenges, the IOC hailed the event as a success.

"With the results we can really take our hat off (to organisers)," Christophe Dubi, the IOC's Olympic Games chief, told reporters, saying that "it is amazing what they delivered considering the difficulties".

"Were the Games perfect? No," he said, adding though that "from an operational point of view everything worked".

The IOC meanwhile published a study claiming Rio 2016's legacy on the city had been "formidable".

"All the venues have a purpose after the Games, the city has been transformed, with a mass-transit transport system," Dubi said.

Despite the IOC's enthusiasm, four months after the Games Rio finds itself severely affected by the historic recession lashing Brazil, with hospitals running out of supplies and civil servants marching in the streets over missing pay cheques.