Israel reportedly provided the intercepted phone calls in which ISIS brag about taking down plane in Sinai.

New reports suggest it was Israel that provided valuable information about the Russian airline that crashed into the Sinai Peninsula, according to CNN.

Officials were initially uncertain what caused the Metrojet flight 9268 to crash last week, but the plane is now believed to have been destroyed by a bomb placed in the luggage compartment. This interpretation is backed up by intercepted phone calls in which ISIS members brag about the attack.

According to a US official, it is these phone calls that Israeli intelligence gave to the US and the UK.

Israeli officials have not commented on the reports.

Earlier today it was revealed that UK intelligence sources believe the attack was carried out by British nationals who joined ISIS.

Egypt says that it remains skeptical about theories that a bomb caused the crash. "We don't know what happened exactly," says investigation head Ayman al-Muqaddam.

Al-Muqaddam added that he has not seen any of the evidence pointing to a bomb.