Citi continues to refuse to discuss its 10 percent stake Al Raya Investment, four days after the Kuwaiti firm's chief executive was found dead.

A New York-based spokeswoman for Citi declined to discuss how the investment came to be, what due diligence was done before the investment was made, and what the Citi plans to due with its stake in the embattled firm.

Al Raya chief executive Hazem Al-Braiken was found dead in an apparent suicide on Sunday after a whirlwind week in which he and two other finance firms were accused by the U.S. Securities and Exchange Commission of having improperly earning millions of dollars from trades in two U.S. firms.

Al-Braikan seemed to be at the top of his career just a year ago, Reuters correspondent Ulf Laessing reported earlier this week.

Last summer, Al-Braikan hosted then chairman of Citigroup Sir Winfried Bischoff, who was visiting Kuwait soon after Citi bought 10 percent of Al Raya. Al-Braikan lunched with Bischoff and even took him to meet Kuwait's ruler.

Earlier this week, Bischoff refused to talk about Citi's investment in Al Raya during an interview with Reuters correspondent Steve Slater.

You have to ask Citigroup on that, Bischoff said.

But we did and they were no more forthcoming.