The Olympic swimming test event, also named as the Maria Lenk Trophy, kicked off on Friday at the recently unveiled Olympic Aquatics Stadium, which is the last chance for the Brazilian swimming star Cesar Cielo.

The six-day event will host over 400 athletes - 356 Brazilians and 57 visitors from 11 countries and regions - and will have competitions in all Olympic swimming events. It is the last chance to swim in the official competition pool for the Rio Olympics.

The venue in the main Olympic Park in Barra de Tijuca was officially opened last week in a ceremony attended by under-fire Brazilian President Dilma Rousseff.

Local eyes will all be on Brazil' s best-known swimmer, 50m and 100m freestyle world record holder Cielo, who faces a tense battle to qualify for the Olympic team.

With a gold and two bronze Olympic medals under his belt, as well as six world championship medals, the 29-year-old is yet to record qualifying times for these two events, his specialties, and has his last chances on Monday (100m) and Wednesday (50m).

Chinese swimming team sent 13 young swimmers to this test event, while its world champions Sun Yang, Ning Zetao and other Olympic squads do not come to Brazil.

"We have just finished the Olympic qualification event in the early of this month, our major swimmers are too tired to take a long journey to Brazil," Xu Qi, Chinese team manager told Xinhua.

"Our aim is to get a taste of Brazil environment and make good preparation for the Olympics. Meanwhile we can train our young swimmers at this international event," he added.

Organized in partnership with the Brazilian Aquatic Sports Confederation (CBDA ), the Maria Lenk Trophy will give the Rio 2016 Organizing Committee an opportunity to test competition management, results operations, venue structures such as the competition and training pools, as well as a workforce made up of 124 volunteers and 74 Rio 2016 employees.