The chief executive of the London Legacy Development Committee, Dennis Hone, told the London Assembly that no matter who takes over the tenancy the £500 million stadium will not re-open until August 2015 at the earliest, and probably not before August 2016.
The four bidders - which do not include the NFL, despite reports that American Football could try to use the venue as a base for a London franchise - have all been told that they must make substantial changes to their proposals to take into account the need to provide covered seating for the 2017 World Athletics Championships, which will be held at the stadium.
"We have no formal bids outside of the competition or otherwise by American football to go in to the stadium," Hone told the London Assembly local authority.
"We are running a competition and we have four bidders. There are no bids outside that."
West Ham are the bookies favourites among the four bidders, which also include Leyton Orient, Intelligent Transport Services - which is trying to turn the stadium into a Formula One circuit - and the University College of Football Business, an academic institution owned and run by Burnley FC that is keen to open a campus in London.
A decision is expected at some point in the first half of next year, prompting criticism from many considering that the LLDC has already spent several years looking at possible post-Olympics tenants for the venue.
But Hone defended the lengthy process, insisting that, "if it takes a couple of extra months to get the right decision for the public purse I will take it, because I don’t want to make a decision that we will regret in three or four years."
The northern area of the Olympic Park - including the Velodrome - is slated to re-open in 2014, while 8,000 homes are also due to be built on the site. The £1.1 billion housing development was originally set to take until 2030 to be completed, but pressure on housing in the south east of England means it is likely to be fast-tracked.