London's bid to host the 2017 World Athletics Championships could be derailed by the legal row surrounding the Olympic Stadium.
Tottenham Hotspur have sought a judicial review of the decision to hand the stadium over to West Ham.
IAAF president Lamine Diack said ruling members would be deterred by a lengthy legal dispute.
"If the legal problems are continuing you must convince my colleagues and many of them will say no," he said.
"If London are to win they have to come and say that they have the full support of the Government.
"They have that and I think they have a good bid."
Diack said the stadium was a "wonderful" venue for athletics but also recalled that Britain had previously pulled out of hosting the 2005 World Championships in London.
The IAAF rejected an offer by the then sports minister Richard Caborn to stage the event in Sheffield instead.
Diack told the Inside The Games website: "Remember, we gave London the 2005 World Championships. Then we were asked by the minister if we would go to Sheffield and we said, 'No'.
"We need to have the answer to the stadium. They have delivered a fantastic stadium. The problem is, are we going to have this continue in the future?
"That is the big problem."
The IAAF will decide on the 2017 hosts in Monaco on 12 November.
West Ham are due to move into the stadium, in Stratford, east London, in the summer of 2013 after winning the race to move on to the site ahead of their north London rivals, who had planned to tear up the athletics track if they were successful
Lord Sebastian Coe, chairman of the London 2012 organising committee and IAAF vice-president, said last month he is confident a bid can proceed, pointing out that Spurs have already lost one court case about a review.
He said: "It really shouldn't prevent it from going ahead. This is a ruling that has already been made.
"This bid can be pushed forward and there is an appetite internationally for this championship to come to London. My colleagues at the IAAF know the reach of GB track and field and we have to grab this with both hands."
Doha in Qatar and an as yet unnamed Spanish city are also bidding.