Indian energy giant Adani will not find out whether it has received an almost $1 billion concessional loan from the taxpayer-funded $5 billion Northern Australia Infrastructure Facility until later this year, just before it is supposed to be delivering financial close on the controversial $16.5 billion Carmichael mine.

Amid growing doubts about whether the Adani project will ever get off the ground, Resources and Northern Australia Minister Matthew Canavan said the seven-person NAIF board was still assessing five proposals, including Adani's rail link, and a decision was not expected until the end of the year.