Mel B was last night accused of making up a romantic encounter with fellow Spice Girl Geri Horner in an attempt to boost sales of her book.
The singer claimed that she shared a night of passion with her bandmate during their 90s heyday – and that they 'giggled' about it afterwards.
But according to an insider, Mrs Horner has privately denied the assertion, which was made during a TV interview to be broadcast later this year.
She is said to believe the claims can be linked to Mel B – whose real name is Melanie Brown – wanting to sell more copies of her tell-all memoir, Brutally Honest. A source close to the band said: 'It's not a very nice thing to do even if you do have a book to promote.
'Nothing ever happened. We all know Mel B loves a headline. It might have been funny 15 to 20 years ago but it was over the top and not funny.'
While recording an episode of Piers Morgan's Life Stories, Miss Brown told the host that the passionate encounter 'just happened'.
She said of Mrs Horner, 46, who married Formula 1 racing team boss Christian Horner in 2015: 'She is going to hate me for this because she is all posh with her country house and her husband, but it's a fact. But it wasn't a thing, it just happened and we just giggled at it and that was it.'
When pressed for more details about their sexual relationship, Miss Brown, 43, said: 'Oh stop it, you pervert', before eventually asserting they did sleep together. In the audience, their bandmate Mel C – whose full name is Melanie Chisholm – said: 'This is all new to me.' Miss Brown, who went through a bitter divorce with her film producer husband last year, added: 'I have said it now. All done. She is going to kill me.'
Although she has not yet publicly refuted the claims, it is thought Mrs Horner is considering making a statement within the next week to 'set the record straight'.
The claim threatens to cause a rift among the bandmates ahead of their reunion tour this summer. Rehearsals for the sell-out shows begin in two weeks, before the first performance in Dublin on May 24.
Miss Brown is known to have a difficult relationship with Mrs Horner – whose departure from the band in 1998 was rumoured to have been due to arguments between the pair. They are said to have already been at loggerheads about outfits for their return to the stage.
The tour is reportedly set to earn the bandmates £2.2million each.
All the former Spice Girls members – including Emma Bunton and Victoria Beckham – remained silent about Miss Brown's claims on social media yesterday. Mrs Beckham is the only one not joining the reunion, which will end at Wembley Stadium in June – 21 years after they performed at the venue as part of their Spice World tour.