Seifeddine Yacoubi Tunisia Isis
Seifeddine Rezgui shot and killed 39 people, mostly Britons, before being killed in Sousse, Tunisia Facebook

As police attempt to piece together the events leading up to the killings of innocent holiday makers on a Tunisian beach, it has emerged that the gunman, Seifeddine Rezgui had waited on the beach for four hours as it filled up with holiday makers in a bid to commit maximum carnage.

A lifeguard on the beach told The Times that Rezgui had arrived on the beach as early as 8am and lay in wait for his victims before embarking on his murderous rampage.

Eyewitnesses described how the ISIS fanatic arrived on the beach on a jet-ski with a parasol which concealed the assault rifle he would soon use to gun down dozens of innocent people.

He then made a final ten-second call to an accomplice before embarking on his bloody rampage killing 38 people, after which he threw his Samsung Galaxy phone into the sea.

Police shot him dead as he headed onto the main road. Images of his corpse revealed an unexploded bomb and a detonator, chilling evidence of the carnage he intended to wreak.

Police recovered the phone from the sea and tracked down the contact who was identified as a known jihadi in Hay al-Tadamon, Tunis, The Times claims.

During interrogations, the unnamed contact revealed that the killer had been recruited by Islamist group Ansar al-Sharia, where in 2013 he attended their meetings and joined their youth wing.

Rezgui and four others - including three known fugitives who are now on the run - were part of a sleeper cell carefully trained by the group in Libya, the suspect said.

It is thought that Rezgui and his accomplices were renting a nearby holiday apartment for up to two weeks ahead of the planned attacks.

The other militants, who have since disappeared, are believed to have returned to Libya where the attack was planned.

It has also emerged that the killer was spotted on the same beach just two weeks before the attack assessing the location ahead of his vicious onslaught.

A hotel worker said he saw Rezgui checking his phone two weeks before the attack.

24-year-old Yasser Madi from Stoke-on-Trent told The Times: "When I saw him I thought he was crazy, not dangerous, but in his face he looked a bit like he was somewhere else... I didn't like him.

He added: "'When I saw him he was a bit weird... He was walking slowly. He was just looking at people. When I saw his picture on Facebook with the machine gun I knew it was him immediately. I said "Oh my god"... everything was the same - same hair, same black flip-flops, black shorts, black T-shirt.'

Meanwhile, the girlfriend of the ISIS gunman has been arrested, it has been confirmed. It's feared the female student may have helped plan the massacre and Rezgui may have spent his last night alive with his partner at her home.

His girlfriend lives in the city of Kairouan, 36 miles west of Sousse, where he was part of a terror cell. The couple are believed to have met on social media and it is thought the woman may be the sister of another jihadi.

According to Tunisian newspaper Assarih she has denied having any knowledge of the plot to murder the holidaymakers.

Eyewitnesses have also reported a second gunman on the scene during the attack.

On Friday the Queen and David Cameron joined the families of the 30 Britons who were killed, in a minute's silence to remember those who died on June 26.