"It’s all complete bulls*** I’m sorry to say," Laundy told News Corp.
"I’ve never met Tiff. I know who Tiff is, we have very close mutual friends and I don’t know how but we have never met face-to-face, ever. Never, ever, ever. I’ll swear on a stack of bibles. I’ll take a lie-detector test!"
The rumours began when the publican was spotted with a 'mystery blonde' in photos published by Daily Mail, whilst Sophie was in Thailand.
"Her name is Katie Adamo, she’s been married for 20 years to the best friend I’ve ever had in my life, so that’s just comical really," he explained.
"That photo was taken on the 23rd of September, it was my best mate Dan’s birthday at Catalina (restaurant) and Dan was there. As a matter of fact I think he might have been taking that photo."
Tonight Sophie will choose between Stu and vineyard manager Jarrod Woodgate.