The trains will boast a total of six carriages and will have a capacity of 964 people, with 454 seated and 510 standing.

One train will run on the Gold Coast line, which provides a connection between the coastal city and Brisbane.

Another will be used on the airport line, with the third train set to be held in reserve.

The New Generation Rollingstock (NGR) trains had initially been expected to run from mid-2016, but a series of technical issues delayed their use.

"Queensland Rail and the Department of Transport and Main Roads have completed comprehensive testing and have confirmed that the trains are fit and ready for revenue service," said Nick Easy, Queensland Rail's chief executive.

"The NGR trains are essential to meeting demand during the Gold Coast 2018 Commonwealth Games and our team has worked around the clock to ensure they were ready this year.

"More trains will be rolled out on the Gold Coast to airport line over the coming months, including some services to Doomben and Northgate, and will eventually operate across the entire South East Queensland passenger rail network.

"The first three trains will be wrapped in an original indigenous artwork, by creative agency Gilimbaa and lead artist Riki Salam, which symbolises pathways across the land to the sea that open up country and connect the people of Queensland.

"As the NGR fleet commences passenger services for the first time, each train's performance will be closely monitored.

"Over the past few months, TMR, Queensland Rail and Qtectic have been working hard to close out the outstanding action items and ensure the trains were safe and ready for service."

Transport Minister Jackie Trad had claimed in May that she hoped 15 of the new trains would be ready for the Commonwealth Games, according to ABC.net.

It is claimed that Queensland Rail have only been able to confirm that three trains will be running for next year's Games out of 21 delivered to Australia. 

Four more are reportedly being delivered from India.

"The timetable for the Commonwealth Games is still under development," Easy said, according to ABC.net.

"The number of trains that will be ready will be on the basis of them passing all the assurance tests and will service the timetable that we will release in the new year.

"We will aim to deploy as many of these trains as possible."

The fleet of trains is also being redesigned due to disability access concerns, with the rectified trains due to move onto the network in 2019.

In October, Trad outlined that upgrades to the Queensland Rail network were on track before the Games, which will begin in April.

The upgrades involved duplicating the last remaining section of single track on the Gold Coast line between Coomera and Helensvale, which was claimed to be crucial to meeting the future public transport needs of the growing Gold Coast community.

New bridges and the refurbishment of stations are also part of the upgrades, which are part of a AUD$163 million (£96.5 million/$128 million/€109 million) project.

Testing on stage two of the Gold Coast Light Rail, a separate project which will provide a tram service to the heavy rail service at Helensvale, began in September.

The 7.3 kilometre light rail extension between Gold Coast University Hospital and Helensvale station is expected to begin running passenger services at the start of 2018.