It will cost about $5.4 billion to build a much-needed second river rail crossing in Brisbane to ease traffic congestion, Queensland's deputy premier says.

Jackie Trad revealed on Sunday the government had received the project’s business case “in the last 72 hours”. When asked whether it gave a better insight into how much the project, previously estimated to be $5.2 billion, would cost, Ms Trad replied: “The cost of this project is in the…