The Englishman admitted that "time is running out" with track cycling due to begin on August 11 and key work still needing to be done.

The official test event at the venue, which had already been pushed back, was cancelled entirely in March, due to delays installing the track.

It was initially supposed to be held between March 18 and 20 but was moved to between April 29 and May 1 before being scrapped entirely.

The test event, known as the Aquece Rio International Track Cycling Challenge, was supposed to be the first event to be held at the venue, but a scaled down trial between June 25 and 27 was arranged instead in order to give the venue a "quick test".

Rio 2016 director of communications Mario Andrada had claimed he was "120 per cent" confident the velodrome would be ready in time for the Olympics, while insisting it would be "Games ready" by May 31, when the test event was cancelled in March.

Organisers also sought to ease concerns over the progress of the Velodrome by staging an "informal test" at the venue last month.

Professional Brazilian cyclists were photographed on the track to aid the fixing of the rubber layer covering the wooden surface, which has been imported from Siberia.

However, Cookson has expressed the UCI’s ongoing concerns with the readiness of the venue with just 71 days to go until the Rio Opening Ceremony.

Track cycling competition is scheduled to take place from August 11 to 16.

“The UCI remains extremely concerned about ongoing delays to the construction of the Velodrome and have raised regular concerns with the Rio 2016 Organising Committee and the IOC,” the UCI President said.

“It has been a very difficult process and the fact that these delays have pushed back any form of test event is very worrying.

“There is still a lot of work to do to ensure that riders have the best competition conditions possible.

“Time really is running out.”

insidethegames understands that the track has now been fully installed at the venue and is not expected to be a concern ahead of the Games, although work is still required on the suspended ceiling system, as well as the heating and cooling system.

The venue is due to have the capability of housing 5,000 spectators, but insidethegames understands the base framework of the seating is currently being constructed, while media tribunes and elevators at the velodrome are also requiring work.