Chief Citigroup web analyst, Mark Mahaney, has been fired after he and another analyst allegedly leaked information to select media outlets about Facebook’s much anticipated IPO.

According to the Wall Street Journal, Mahaney and Eric Jacobs were dismissed after the investment bank became aware of the pair attempting to cover up a violation of the bank’s protocol on responding to media requests in April.

Mahaney produced influential research for Citigroup on a number of web giants including Amazon, Google, Yahoo and Groupon.

Massachusetts’ securities regulator fined Citigroup £1.24 million on Friday for failing to properly supervise Mahaney and Jacobs.

The news comes as a further blow to the troubled Facebook IPO, which now faces a number of investigations over unsavoury practices and technical glitches.

Federal and state regulators are investigating a number of the banks that underwrote Facebook’s IPO after investors have reportedly lost billions of dollars as the social network’s shares have continued to tumble.

Questions have been raised about the way in which Facebook shared information about its exit with its major underwriters, and then how these banks selectively shared financial warnings with its major investors, whilst leaving smaller players in the dark.

Citigroup recently slammed Nasdaq’s £39.2 million compensation plans for market making firms that lost money during the botched IPO on 18th May. In a letter sent to the US Securities and Exchange Commission, Citi said that Nasdaq’s actions amounted to ‘gross negligence’.

The IPO was riddled with technical problems, which led to a delay of 30 minutes on share trades being processed. The problem stemmed from Nasdaq’s IPO Cross – a pre-IPO auction process that the exchange put in place in 2006 that allows traders to place orders and agree on an IPO price before the stock is officially launched – which couldn’t handle the trading demand.

Nasdaq has made it clear to firms that suffered losses that its decision to offer compensation is voluntary and it isn’t obliged to reimburse for the full amount. It has also given strict parameters as to which type of orders can be reimbursed, and has said that firms that claim the compensation will lose their right to sue the exchange.