The Chester Chronicle's sister paper The Liverpool Echo has revealed vital CCTV images of the 24-year-old from Guilden Sutton , captured just hours before she was reported missing from the Disney Wonder vessel on March 22, 2011.
They show the former Chester Catholic High School student visibly distressed as she talks on an internal ship phone, near the crew cabin area, at around 6am, seeming so upset that a male employee stops to check if she is OK.
After ending the call, as the ship sailed in Mexican waters, near Puerto Vallarta, Rebecca appears bereft, holding her head in her hands with desperation.
She also appears to be wearing a man’s clothes, which she repeatedly pulls at uncomfortably, a sign she is extremely unhappy about a recent incident, private investigators said.
Rebecca's family believe what had happened to their loved one, just before the call, is the key to her disappearance, and presumed death.
The footage was shown to Rebecca's parents Mike and Ann Coriam when they flew to Los Angeles, where the ship had docked, days after the tragedy.
Disney officials always insisted these last-seen images of Rebecca were taken on Deck 5, not far from the door to the bow where, they say, the former Liverpool Hope University student was later swept overboard after a freak wave.
But the CCTV, with a date, time and the camera's location clearly on the bottom of the video, state the phone call was instead made from Deck 1.
Private investigators say that fails to fit with the theory insisted upon by Royal Bahamian Police and Disney because Deck 5 is four flights of stairs away.
And they think Rebecca was instead heading to the nearby Deck 1 medical centre when she disappears off camera.
The probe into the student’s death has been comprehensively slammed by senior political figures including ex-Labour deputy Lord John Prescott who has suggested the ship youth worker was ‘thrown over the side’, and ex-shipping minister Mike Penning who described the enquiry as ‘appalling.’
The independent team helping Rebecca’s family, including Chester MP Chris Matheson , think ‘criminal activity’ was behind the student’s sudden vanishing.
Bill Anderson, leading the independent investigators, said: “The CCTV clearly shows Rebecca, upset, wearing a man’s clothes, grabbing her head.
“The CCTV data show this is Deck 1, not Deck 5, where she supposedly accidentally fell overboard.
“If she did go to Deck 5, where a pair of flip flops claimed to be Rebecca’s were found close to the edge of the ship the family were told, she would have got the lift up from Deck 1.
“But this camera clip demonstrates she ignored the nearby lifts to get there, so that explanation doesn’t fit.
“We think Rebecca is talking to a cabin mate about something awful that has happened.
“Our suspicion is, not long after this clip, she is thrown overboard.”
It is claimed Mike and Ann Coriam, when meeting Disney in Los Angeles, were only shown cropped images from this CCTV, and not the full clip, showing the actual deck number where the phone call happened.
Earlier in March, it was claimed how the flip flops handed to Rebecca’s heartbroken parents, when returning her possessions, did not belong to her.
The footwear, said to have been left on the edge of the ship where Disney reckoned she fell overboard, bore a different signature and cabin number.
The Coriam family have queried how their daughter could have been swept over a 6ft-plus high wall, where Disney later laid flowers on deck to mark the tragedy.
Last month, Rebecca’s favourite shorts were ripped when they were handed back to her parents, raising questions as to whether this was evidence of a violent struggle just before her death.
Disney declined to comment.