Citigroup (C) almost credited a wealth management customer's account with about $6 billion by mistake in April last year due to a copy-paste error, Bloomberg News reported late Monday, citing people familiar with the matter.

The amount is more than a thousand times the intended figures for crediting the account, and the error was detected the following business day, the report said.

The incident occurred in the same month that another Citigroup division mistakenly credited a client's account with $81 trillion. The company has since established a tool to assist with the review of large transactions, the news outlet quoted sources as saying.

Citigroup did not immediately respond to MT Newswires' request for comment.

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