Greensill Capital creditors want a new Federal Court judge overseeing some $7 billion in legal claims against insurance giant IAG to disqualify himself, arguing there is a question about whether he might be seen to be biased because he previously acted for one of the parties.

Cameron Moore was appointed to the Federal Court late last year and is the fifth judge to hear the slew of claims filed against ASX-listed IAG, which issued insurance policies worth billions of dollars to the collapsed financier.