By Nick Butler

Rio 2016 insist that improvements are taking place, including in the much maligned Deodoro Cluster where equestrian is one of nine sports to be held ©Rio 2016/Alex FerroRio 2016 have hit back at critics who claim venues will remain incomplete when the Olympic and Paralympic Games begin in a little over two years' time, by insisting 38 per cent of venues are already completed and there is progress with all the others. 

Following the bombardment of criticism received in recent weeks, a statement released today by Brazilian officials claims "construction progress can be seen in the four Rio 2016 competition zones".

Of the 29 permanent venues, it claims 11 are operational, eight require some renovation work and the other 10 will form part of the sporting legacy being constructed in the city, while there will also be eight temporary venues used to host competitions.

In particular, in the main Olympic Park in Barra de Tijuca, the foundations have now been set for Olympic Halls 1, 2 and 3, where basketball, judo, wrestling, fencing and taekwondo will take place.

The nearby golf venue site is now being irrigated in order to allow grass planting to begin.

At Lagoa Rodrigo de Freitas, venue for rowing and canoe sprint, depth studies have been completed, while at Flamengo Park, the design of the integrated route for the athletics, road cycling and Para-cycling courses has started, it was added.

But all of this is unlikely to alleviate concerns, with fears remaining over pollution levels in the Lagoa, as with venues for other water sports.

Earlier this week, International Golf Federation vice-president Ty Votaw expressed fears over the likelihood of a Rio 2016 Olympics golf test event being able to take place in one years' time, despite the progress.

The Maracanã Stadium is one venue already completed ahead of it hosting the FIFA World Cup final on July 13 ©Getty ImagesThe Maracanã Stadium is one venue already completed ahead of it hosting the FIFA World Cup final on July 13 ©Getty Images

Most significantly, at the second major Games hub in Deodoro where seven Olympic and three Paralympic disciplines will take place, the statement admits that while the tender process is underway, construction is not scheduled to start until later this year.

International Olympic Committee (IOC) Executive Director Gilbert Felli admitted this construction is running two years behind schedule last week, while IOC vice-president John Coates claimed preparations were the worst he had experienced in his long association with the Games.

It is hoped that with three of the venues on the site only requiring renovation - for shooting, equestrian and modern pentathlon swimming - and two other temporary venues to be installed, where mountain biking, modern pentathlon and rugby will take place, the construction process will be relatively simple.

The biggest obstacle appears to be preparations for the four new venues, the Olympic BMX Centre, the Olympic Whitewater Stadium, the Olympic Hockey Centre and Deodoro Arena, which will host the fencing part of modern pentathlon, some basketball matches and wheelchair fencing.

The statement today bills these four new venues as "part of the important sporting legacy the Games will leave to the city".

"We are advancing in the construction of competition venues for the Rio 2016 Games, with all of the basic and executive projects concluded or in the conclusion phase, and with foundation works in full flow," said Rio 2016 infrastructure integration director Alexandre Techima.

"Even though they may not be highly visible, the preparative groundwork and foundation construction, that occurs underground, are extremely important for the final structure and often account for 20 per cent of the total volume of construction."

Work is also finished on the venues for football, archery, athletics and volleyball in the Maracanã Zone to the north of the city, as well as on the four sites outside Rio where football will be held, in Salvador, Brasilia, Belo Horizonte and São Paulo.

But no update has been provided on measures taken to improve the sailing venue at Guanabara Bay, which has been dogged by pollution fears ahead of a test event due to begin on August 2 this year.