A video has emerged that appears to show the Tunisia gunman Seifeddine Rezgui moments after he had opened fire on a popular tourist beach in the resort city of Sousse.
The 24-year-old graduate of Tunisia's Kairouan University can apparently be seen running along the surf with a Kalashnikov assault rifle at his side, before he cuts in towards land and makes his way up between two hotels.
Witnesses have previously said that it appeared as though Rezgui knew the layout of the Hotel Rie imperial Marhaba, where he continued the attack before he was shot dead by police.
And as the video emerged, investigators in Tunisia said they were still searching for at least one accomplice to the attack that killed 38 people.
The father and three roommates of the attacker have been detained for questioning in the capital of Tunis, an Interior Ministry spokesman said.
"We are sure that others helped, but did not participate," the spokesman said. "They participated indirectly."
A security official close to the investigation confirmed news reports indicating that a swimmer had found the attacker's mobile phone in the Mediterranean.
The phone showed the attacker spoke with his father just before his assault, the official said.
Authorities believe the suspected accomplices provided the Kalashnikov assault rifle to Rezgui and helped him get to the scene. Ballistic tests showed the bullets came from that single weapon, and the attacker was carrying four cartridges of ammunition - all were found by investigators, he said.