The man behind the project, American art dealer Kenny Schachter, wants to significantly expand the original proposals, having splashed out on a neighbouring plot.
The scheme, which has gone through a number of revisions on its three-year journey through Hackney's planning process, was expected to become Hadid's first completed building in the capital, beating her high-profile and much-troubled Architecture Foundation (AF) project.
However, it is now unlikely that the redesigned gallery, office and apartment will finish before the AF building, which is due to open in 2008.
Schachter originally won permission for a smaller, but similar, scheme on the site back in March 2006 (Zaha's Hoxton Square proposals finally win planning) following a two-year wrangle with the planners.
It is understood the revised proposals, which will replace an existing 1980s building and the next-door block, will increase the street frontage outlined in the earlier plans by up to 50 per cent.