The Japanese consortium pitching to build Australia's $50 billion fleet of new submarines has denied reports that Australian officials have been forced to chase them for basic information including a detailed budget for their bid.

Shunichi Miyanaga, the president and CEO of Mitsubishi Heavy Industries, said in Melbourne that Japan's bid was making "very smooth progress" as it is raked over by experts from Australia's Defence Department.

Shunichi Miyanaga says Japan's bid is making "very smooth progress". Credit:Wayne Taylor

MHI and Kawasaki Shipbuilding Corporation, led by the Japanese government, is in a three-way contest against Germany's ThyssenKrupp Marine Systems and France's DCNS to build 12 new boats to replace the Collins Class submarines.

A report out of Tokyo this week by The Financial Times said Japan's inexperience in selling major military hardware abroad meant its bid had been vague in its commercial terms, lacked a detailed budget and failed to specify which company was leading the project.