The 35-year-old judge sparked a frenzy on Twitter when she appeared more overexcited than usual and bounded onto the stage striking poses and waving her arms in the air.
Nicole seemed to be in very high spirits as she cheered on her contestants during their performances.
"Is Nicole Scherzinger drunk right now? Serious q," wrote Twitter user Miguel Caycedo.
"Sometimes I think that Nicole Scherzinger has been drinking before xfactor because the stuff she says sounds like drunk people talk," wrote another viewer, Chelsea The Vamps.
Nicole had reportedly thrown a party in her dressing room before the live show, for her family who were visiting from Hawaii.
"Nicole had been to see her girls during the day and knew they were going to do well with the disco theme that night so she was pretty relaxed and decided to kick back by having a party," an insider told The Sun.
"Her family were over from Hawaii, and before the show she was dancing and spinning disco classics for them. Everyone was pretty excited and went a bit wild."
According to the publication, show bosses investigated viewers' claims to find out whether Nicole had enjoyed a drink.
"After the Twitter reaction from viewers, staff did ask her people if she'd been drinking and they said she hadn't," the source added. "There wasn't any evidence of empty bottles in her dressing room afterwards."
"Nicole wasn't drunk," an X Factor spokesperson confirmed. "She was just excited and getting into the disco spirit."
The former Pussycat Dolls singer seemed more subdued on Sunday night's episode when one of her girls, Tamera Foster, was placed in the bottom two against boy band Kingsland Road.
The band was voted off, with their mentor Gary Barlow disappointed at his fellow judges' decision.
"These guys were together two years before they joined us," said Gary. "They should stick together because they will be a hit band. I just want to remind everyone this is a singing competition — that's all I need to say."