The Coronation Street star took to Twitter yesterday afternoon (August 4) and posted a message saying: "What now?????!!!!! ...Don't believe everything u read!!!! #laughable."
The Mirror had claimed that Keegan and Thomas - who plays builder Jason Grimshaw in the soap - were spotted enjoying "an intimate dinner at a Manchester restaurant" last week and quoted a source as saying that the pair "seemed like a couple out on a date having a good time".
"I have that many teeth marks in my tongue 4 having to keep biting it when I see incorrect stories about MY life," Keegan added this morning (August 5). "It's unbelievable! #notfair."
The actress is also said to have denied that she and her former fiancé, The Wanted singer Max George, have reconciled. The pair recently confirmed their spilt after photos of George kissing a blonde woman in a Newcastle nightclub were published in The Sun.