Tunisia gunman Seifeddine Rezgui 'made a 10-second phone call' before opening fire on beach

The hotel shooter is thought to have been part of an Isis 'sleeper cell'

A video posted online appeared to show police retrieving Seifeddine Rezgui's phone from the sea

Police in Tunisia say the gunman who shot dead 38 people on a busy tourist beach made a 10-second phone call just before he opened fire in Sousse.

Investigators are still trying to establish who it was that 23-year-old Seifeddine Rezgui contacted in what he must have known would be his last moments, but have previously said he was likely part of an Isis sleeper cell operating in Tunisia.

Rezgui’s white Samsung Galaxy mobile was retrieved from the water next to where the shooting occurred after 6am the following morning, in front of the Imperial Marhaba hotel.

The amount of data on the phone, if it has not been lost, could prove vital in establishing the size and strength of the terror network.

Police divers retrieved Rezgui's phone from the sea after 6am the morning following the attack

On Tuesday, police in Tunisia released images of two men being sought in connection with last week’s attack, in which up to 30 Britons are thought to have been killed.

The photos are of two men identified as Rafkhe Talari and Bin Abdallah, though their connection to the deceased gunman Seifeddine Rezgui is not clear.

Police have questioned Rezgui’s father, Hakim, and arrested seven suspects associated with the gunman.

Interior Minister Najem Gharsalli said that forensic evidence suggests Rezgui, who was shot dead by police after a 47-minute rampage, was likely to be the only shooter in the incident.

But officials have said it is also likely that he had accomplices who provided the Kalashnikov rifle used in the attack and helped keep his activities secret.

“We will find all those involved, whether it was just logistical support or not,” the Mr Gharsalli said.