The second series of the show, which has been attracting around 5.5m viewers on BBC One, has been heavily criticised by Mediawatch UK for showing high-profile references to Moet & Chandon, Champneys health spa and Pets at Home, including lengthy close-ups of product logos.
The BBC has strict editorial guidelines on not allowing product placement, and programme makers are required to "editorially justify" all close-ups of brands, verbal references and "name-checking."
The BBC has strongly denied assisting advertisers on 'The Apprentice' or giving "undue prominence" to brands.
John Beyer, director of the viewers' association founded by the late Mary Whitehouse, said: "It does seem to me that the name of the services and hotels is something that is unduly prominent.
"I think that there is a lot of what I might call placement advertising. I think there's a case for the BBC Trust to look into."
Beyer added that "accidents" could occur where programme makers inadvertently advertise products "but it seems...'The Apprentice' is doing it by design, and the BBC is in some way assisting that".
Incidents criticised by Mediawatch UK include the fleet of Chrysler Grand Voyagers that appear in every episode, extended shots outside Pets at Home -- including references to how many stores it has nationwide -- and contestants reading brochures for Champneys.
Champneys later issued a press statement referencing its appearance on 'The Apprentice', which the BBC is understood to have asked it not to do.
A BBC spokesman said: "There is no question of product placement on 'The Apprentice'. The use of brands is entirely editorially justified to highlight the desirability of the life the successful candidate will enjoy."
The series, which is produced by Talkback Thames, pitches a group of businessmen and women against each other to win a job at Sir Alan Sugar's electronics company Amstrad.
It is not the first time that the BBC has been accused of allowing product placement in its output. In September 2005, the BBC Trust launched an enquiry into claims that companies were paying up to £40,000 to get products featured on the corporation's programmes, including hit espionage series 'Spooks'.
One episode of 'Spooks' featured eight references to brands and services, but the programme makers responded that the appearances were only there to offer authenticity and realism.