The 33-year-old X Factor USA star has been happily dating the racing driver, 26 , for four years, but they have no current plans to tie the knot.
She wrote: ‘Lewis and I woke up this morning and read we were engaged! Sorry to disappoint u all but its not true:)’
Scherzinger’s statement is at odds with an interview given by her own father, in which he categorically stated that the pair are betrothed.
Alfonso Valiente said in an interview: ‘You know about the proposal? Yes they are engaged.’
He then added: ‘My future son-in-law is a really nice guy, really down-to-earth. My family all like him. The good spirit is there.’
The Pussycat Doll’s father then fondly recalled his first meeting with the Hertfordshire born world champion last summer in Oahu, Hawaii.
‘That went down very well,’ he gushed. ‘He is sincere and he and my daughter seem genuinely happy together, Lewis is a really good guy.’
‘When they came to visit, we hired them a Jeep because he had never driven one before.’
The couple started dating shortly after meeting each other at the European Music Awards held in Munich in November 2007.
Of the seven-year age gap between his daughter and Lewis, her father laughed nervously and said: ‘You have to ask her about that.
‘I have always seen them as a match. I don’t think age matters when you have energy and a connection like they do.’
Scherzinger lives in a £2.4 million French Polynesian house on two acres of land in the Hollywood Hills, while Hamilton is based in Geneva, Switzerland.
However, they’re spending time together in L.A. currently, they enjoyed an trip to a bowling alley with boxer Amir Khan.