Could the picture above hold the key to finding Ed Gillespie?
Walking through the very marina Ed was last seen in, in the early hours of the 22nd December
So far police have spoken to more than 100 people who were at Roydon marina that night - but they're desperate to trace this woman, to see if she can provide them with any new information.
Ed hasn't been seen since leaving a Christmas Party at the Roydon Marina Hotel. His glasses were found close by, but there haven't been any other clues.
Searches have been carried out on the marina, and nearby waterways with police using an underwater robot to help scour the river bed.
The police still have no hard evidence to indicate what's happened to the 38 year old.