Jamie Lee Warn denies murder and two counts of perverting the course of justice.
Andrew Carpenter, who often works with the States police, said that both Miss Besenyei’s mobile and Mr Warn’s were registering with a cell tower close to his First Tower home on 10 May, the last day the 37-year-old was seen alive.
The Crown alleges that Mr Warn killed her that day and then kept her body hidden in the boot of her car for three days before dumping her in the sea at a remote bay in the early hours of 14 May.
It is claimed that Mr Warn moved her car to First Tower car park until that time.
The jury of six women and six men were told that Mr Warn’s mobile connected with a number of different cell sites seemingly heading in a westerly direction along the northwest coast between the hours of 12.30am and and 1am on 14 May.
Ms Besenyei’s body was discovered seemingly floating in a bed of seaweed at Le Pulec Bay just before 5pm on 16 May by a dog walker, jurors were told.
The man said he was in the area of Le Pulec with his dog when he noticed something in the water. He could not tell what it was so he pulled out his binoculars.
‘I noticed what looked like jeans,’ he said in a statement. ‘I moved from where I was standing as it is a slippery area. That’s when I saw her torso. I could not see a head, it was covered with seaweed.’
The man then called a relative who worked for the Fire and Rescue Service to report what he had seen.
The jury also heard from two firefighters who attended the scene.
Watch commander Richard Ryan told the court he had helped to move Miss Besenyei’s body into a body bag.
He told the court the body seemed to be floating in seaweed and may have been resting on a rock.
And he told the court he noticed bruising on the right side of her chest and ‘some kind of purplish discolouration on the left’.
The trial continues.
