The former Pussycat Doll said that the pictures were not what they seemed and the pair were "just talking".
"You are always going to have people saying something or having a picture," she told The Sun.
"But it is complete dross if you and your partner know what the truth is.
"Chris Brown and I are definitely just mates. I have known him since he was younger than 16.
"We were just talking. Even my mum said, 'I saw a picture of you'. It's the same when Lewis [Hamilton] had some random girls sitting in the lobby."
In July, Scherzinger's on-off boyfriend Lewis Hamilton was said to have invited a group including ten girls back to his hotel room after a night of partying in London. The F1 driver later apologised to Scherzinger and the pair reconciled.
"Can't girls just be sitting in the lobby?" the X Factor judge said of the incident. "Maybe they were going to the same party.
"Every relationship has its things and you work it out. We made it last for four years so far, so it definitely makes things interesting and challenging."
Hamilton currently spends the majority of his time in Monaco, while Scherzinger recently snapped up a central London residence where she plans to stay for the remainder of this year's series of The X Factor.
"I wouldn't wish a long-distance relationship on anyone, Lewis would say the same," said Scherzinger of the arrangement.
"But if it's worth it, you fight for it. We try to see each other as much as possible."
The singer explained that Hamilton had flown in to be with her on his way to this weekend's Indian Grand Prix and even paid a visit to the X Factor set.
She said: "Lewis was backstage. He enjoys it and is supportive of me. I don't care whether he felt like he was dragged there.
"He wants to support me [and] I am there for him and his races."
The X Factor continues tonight at 8.20pm on ITV1. Viewers will see Scherzinger's contestants - including controversial act Rylan Clark - competing against the groups, girls and over 28s while singing songs that fit a Halloween theme.
Photo Gallery - X Factor live show week 3:
Copyright: Ken McKay/Thames/Rex Features