The model invited the Doctor Who star, who she apparently separated from in November after an on-off relationship of 19 months, to a meal celebrating her 23rd birthday at a London restaurant last week.
"They looked really cosy and loved up," an onlooker told The Mirror. "Daisy looked gorgeous - Matt couldn't take his eyes off her."
Since the apparent reunion, Murs has responded to suggestions that Lowe is attracted to him by admitting that he has no idea what she looks like.
"I'll need to see a picture," he is quoted as saying. "But I'm open to it."
However, Lowe took to Twitter on Sunday (January 29) to express her disgust at the idea of a romance with the singer.
"As IF i could EVER have a crush on olly murs!!! YUKKKKK #vomitinmymouthandmyears," she wrote. "Hes said i had a crush on him!!! And i DONT!!! Yukkkkk."
Smith and Lowe are believed to have spent the night together last month, prompting insiders to comment that they could reunite in the near future.