The latest series of the Simon Cowell talent contest featured multiple product placement deals, but one episode in particular has landed it in hot water.
During the first instalment of Judges' Houses on Saturday 21st October, certain scenes clearly featured the mobile network Three.
The first came when the Girls category flew to Dublin, only for Louis Walsh to surprise them with the news that they'd actually be going to San Francisco.
As the contestants celebrated, a crew member handed them a mobile phone with a large Three logo on its back.
The anonymous staffer said: "Now you know that you're going to San Francisco, here's a phone from Three to call Sharon when you arrive."
Later, once the Girls had reached their destination, they received a text from their mentor Sharon Osbourne on the device. Again, the Three logo was clearly visible.
The branded mobile was seen once more when Rai-Elle Williams called her family to reveal she'd made the live shows.
According to The Mirror, Ofcom is now reviewing the offending episode to determine whether it featured Three too prominently.
A spokesperson for the media regulator said: "We’re investigating whether this programme broke our product placement rules."
It is unclear whether any viewers got in touch to complain about the matter.
Ofcom has permitted product placement in certain UK television programmes since February 2011.
However, the broadcasting code states that such references must not be "promotional" or "unduly prominent".
The X Factor previously fell foul of prominence rules with its ninth series in 2012.
Ofcom found that one episode had too many references to London's Corinthia Hotel, where contestants resided during the live shows.