The inquiry, headed by the clinical psychologist and TV parenting expert Tanya Byron, is expected to shine a light on the industry's existing code of practice, which covers pop-ups, banners and other paid-for space, but does not apply to editorial content.
In a consultation paper on Tuesday, ministers asked: "What roles do the retail and advertising sectors play in child safety online? For example, how is the internet and means of accessing it marketed and sold to children and young people, and what role does online advertising play?"
It also asks what the advertising and retail sectors do to support children, young people and parents "to manage potential and actual risks in playing video games", and how games are marketed and sold to children and young people.
Baroness Peta Buscombe, the chief executive of the Advertising Association, said the AA had already brought together representatives from agencies, new and traditional media and advertisers to find "a solution that is robust, fair and workable, and to future-proof the self-regulation of digital media".