The admission follows reports last week that the blonde beauty shared a passionate night with the couple, both 41, when they first married in in 2007.
The socialite, 40, also spoke of the former Spice Girl's suffering at the hands of Belafonte, claiming she 'couldn't leave initially leave as he controlled her finances'.
Speaking to The Sun, Lady Victoria revealed:
'She said he controlled all her finances and she wasn't initially strong enough to leave him.
She said she waited until everything fell into place before she could do it and finally everything fell in to place and she knew it was time. No woman should suffer like she has, I feel terribly for her.'
Addressing the night they spent together, she explained that Mel reached out to her via Instagram, adding:
'Mel said she just doesn't know if videos exist of that night but she reassured me that they are unlikely to be coming out.'
It also followed a picture that resurfaced purporting to show Stephen in a clinch with two women, one - he joked - being his wife.
The friend of Lady Victoria previously told The Sun:
'It was all a blur and everyone was very drunk, especially Lady Victoria.
'She told me one minute they were laying in bed watching a movie together, then they got carried away and Stephen was on top of her and Mel was kissing her.
'Next thing she can remember they all woke up naked in bed in the morning.'