A man suspected of involvement in the deadly attack on a U-S diplomatic compound in Benghazi is being held in Libya.

That's according to two sources -- one of them who was briefed on the arrest by Western intelligence officials.

Both sources confirm the man arrested is Faraj al-Shibli -- who was a member of a militant group that tried to overthrow the Gadhafi regime in the 90s.

He was detained within the past two days and had recently returned from a trip to Pakistan.

It is not known whether he has been charged.

The September 11th attack on the U-S Consulate left four Americans dead, including U-S Ambassador to Libya Chris Stevens.