According to The Sun, the two-and-a-half clip shows the pair, who split in 2015, lying on a bed together while being intimate and it has been viewed by at least 286,000 times since it was shared.
A source told the newspaper: ‘Nicole will be heartbroken that such footage has found its way online’.
The insider added that steamy bedroom video of former X Factor judge Nicole, 40, and sports star Lewis, 32, was reportedly not intended for the ‘public domain’.
The pair split for the fourth and final time in 2015 after dating for eight years.
See clip preview below…