Wall Street powerhouse Goldman Sachs is raising eyebrows again after it disclosed earlier this week that it had amassed a 7 percent stake in Ion Media Networks.

The bank also advising General Electric’s NBC Universal in the media giant’s bid last month with hedge fund Citadel Investment to buy out Ion and take it private.

The stake raises the question of whether Goldman bought Ion shares because information might have slipped over the so-called Chinese wall, which is supposed to prevent one division from using its insider access to the detriment of outsiders.