The investor has also called on the board of Rangers International Football Club to realign itself around chairman Malcolm Murray, declaring it bought shares on the strength of Mr Murray's City background and lifelong support of the club.
The institutional investor, speaking on condition of anonymity, declared it had never seen scandal engulf a company so soon after a flotation.
A senior executive at the investor said: "Within four months of the IPO [initial public offering], we have this scandal."