It is believed that Dean is single following relationships with Brooke Shields, Mindy Mc Cready and Playboy Playmate Samantha Torres.
Are celebrities more likely to divorce or break up?
The 27-year-old former swimmer was spotted out and about with Dean Cain, who she met while starring on Channel 4 reality show The Jump.
In the snaps, which were taken last week, Rebecca and 49-year-old Dean can be seen strolling along the streets of London after apparently going for lunch together.
Earlier this week news reports surfaced that Dean Cain, 51, and his partner had split up.