The study was set for completion in June under the terms of a tender issued by John Holland Rail, which manages and operates the NSW regional rail network on behalf of the state government.

But on July 4, mayors and general managers from the three NSW councils affected by the proposed railway line were told during a briefing in Cooma that the study was due to be completed by the end of 2019.

A Transport for NSW spokeswoman confirmed the timing in a one-line statement to the Sunday Canberra Times.

The statement did not address questions about who was awarded the contract to carry out the study and when the NSW government expected to make a decision on whether it would fund the proposed railway line.

In August last year, the NSW government announced $1 million in funding for the feasibility study.

The move followed the release a month earlier of a concept plan developed by engineer Edwin Michell on behalf of the Cooma and Monaro Progress Association.

Mr Michell's plan proposes to rebuild and reopen the disused rail line between Queanbeyan and Bombala. The tracks would be extended north to Canberra Airport and south to the Port of Eden.

The route has eight potential stations - Canberra Airport, Michelago, Bredbo, Cooma, Nimmitabel, Bombala, Towamba and Boydtown in Eden.

The primary purpose of the railway line would be freight movements and easing the impact on roads, but passenger journeys are also incorporated in Mr Michell's concept plan.

The plan estimates the cost of construction as being $2.27 billion, or $2.95 billion including contingency funding.

The disused railway corridor between Queanbeyan and Bombala is also the subject of a separate proposal that would result in cyclists and hikers using the tracks.

A feasibility study on the Monaro Rail Trail is under way, with community consultation sessions held in Michelago, Bredbo, Cooma, Nimmitabel and Bombala this week.

The Snowy Monaro Regional Council has appointed planning and design firm Transplan to carry out the rail trail consultation.