The TV watchdog will be looking into 20 complaints back from August over remarks Christopher Biggins had made regarding bisexuality.
During his time in the house, Biggins made a number of comments about "the bisexuals", remarks that eventually contributed to his removal from the house by show bosses.
"We're investigating whether a contestant's comments about bisexual people were offensive and breached generally accepted standards," a spokesperson for Ofcom confirmed.
At the time the show aired, many viewers blasted Biggins for his comments.
"Bisexual erasure angers me! And it's a shame that it even occurs within the LGBTQ+ community! Disappointed with Biggins! #CBB" one viewer wrote.
Another agreed: "So disappointed in biggins a GAY man and prominent member of the LGBT community erasing bisexuality like that what an idiot #BBUK"
But while Biggins' comments will be looked into, the television regulator has also dismissed more than 400 other complaints about this summer's show.
Objections ranged from accusations of race discrimination to footage of sexual material.
During the show last month, various incidents prompted complaints including Marnie Simpson and Lewis Bloor's naked 'romp' in the shower to Aubrey O'Day spitting in Stephen Bear's food and drink.
There were also Bear's daily pranks and claims of bullying.
But Ofcom said the complaints did not raise issues warranting investigation.
While Celebrity Big Brother still notched up almost twice as many complaints as any other programme in August the numbers were actually some of the lowest for the show.
The last series of Celebrity Big Brother back in January finished with a total of 2,025 complaints to Ofcom, and that was 500 down on the previous winter run last year.