According to ABC News, documents obtained by reporters state that Citi did business with a Florida company which has been implicated for using so-called "robo-signers", but senior executives at the bank refuted any such suggestions.
"We have not found evidence of robo-signing. We are fairly confident we have not relied on robo-signers," said finance chief John Gerspach.
However, Mr Gerspach's public pronouncement was called into question by one-time labour secretary Robert Reich, who said some businesses in the financial sector had been "extraordinarily rapid and careless" when lending money to buyers.
Earlier this week, the Bank of America revealed it would again begin to submit foreclosure documents to courts in 23 American states, effectively lifting a freeze which it had put in place at the start of this month.
By Claire Archer