Haunting text message found on phone of #ISIS terrorist who massacred 84 people in Nice

Forensic experts are combing through Mohamed Lahouaiej Bouhlel's phone and computer to find if anyone else is linked to the attacks

Anti-terror police found a haunting text message on a phone belonging to truck terrorist Mohamed Lahouaiej Bouhlel that read: "I have the material."

The latest revelation backs up a theory from French detectives that a secret ISIS-linked terror network may have planned the attacks that massacred 84 people.

It was unclear what 'material' he might be referring to but a weapons cache including guns and grenades was found in the back of his rented truck.

French prosecutors said 31-year-old Bouhlel had driven down the Promenade twice in the days leading up to the attack.

He scouted the Promenade des Anglais on Tuesday 12 July and Wednesday 13 July and could be seen observing the scene 'very carefully', reports Europe1.

After the attack investigators found a four-word message sent from his mobile that read: "I have the material," reports Nice Matin.

Forensic experts are tracing the recipient's number as they comb through Bouhlel's computer to uncover if anyone else is linked to the attacks.

Yesterday ISIS claimed responsibility and also released a video glorifying the slaughter of innocent families.

And this morning detectives swooped to arrest a man and woman who remain in custody along with five other suspects including his ex-wife.

BREAKING: ISIS affiliated Amaq Agency claims responsibility for #Nice truck attack. - @N_Heninpic.twitter.com/QlkamyxKc8

— Conflict News (@Conflicts) July 16, 2016

Before the attack Bouhlel made a chirpy phone call home before sending brother Jaber a snap of himself posing with pals in the French resort at 4pm.

At 10.30pm the Tunisian, who was on medication to control his rages and said to suffer severe psychotic attacks, drove a 19-tonne articulated lorry through crowds watching a fireworks display on the Promenade des Anglais, and was shot dead by police.

Brother Jaber Bouhlel, 19, said: “He sent a selfie and told me he was happy and everything in his life was normal.