The N-Dubz singer starts each show by holding her arm up sideways revealing a tattoo saying, The Female Boss, which is the name of her new fragrance launched last month.
The media regulator has received a number of complaints that showing the tattoo breaks rules governing the promotion and reference of commercial products by on-screen talent.
Ofcom is also said to be investigating a segment in ITV2 spinoff show, The Xtra Factor, which referred to The Female Boss and discussed Tulisa's signature gesture.
The watchdog will judge whether brandishing the Female Boss tattoo so clearly to the camera is in breach of its broadcasting rules, reports The Guardian. Should the regulator decide that it is, Tulisa could be banned from doing the gesture in future broadcasts.
Ofcom has not yet decided whether to launch a separate investigation into swear words emblazoned on Rihanna's shoes during last night's X Factor results show.
The ITV1 series has regularly got into trouble with Ofcom, including a ruling in January that the show was in breach of product placement rules after presenter Dermot O'Leary appeared to encourage viewers to download songs from guest acts on the programme.
Last month, ITV1's This Morning programme was criticised by Ofcom for allowing Britain's Got Talent judge Amanda Holden to promote a group of law firms she was backing.
> X Factor Results Show, Rihanna, Rebecca Ferguson - Pictures
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