Reports in the Spanish media have claimed that midfielder Benitez tested positive for cocaine after Granada's 1-0 win over Real Betis in February.
Benitez came on as a substitute in that game before being sent off after just 19 minutes for a rash challenge on Betis midfielder Nono.
The 26-year-old has spent almost five years on loan at Granada from Udinese as part of a partnership agreement between the two sides.
It has been rumoured that Granada's legal team have already informed Benitez of their intention to rescind his deal at the club.
But Granada have not received official notification from the Spanish Agency for Health Protection in Sports or football's governing bodies, and club director and spokesman Pedro Gonzalez Segura insists they will not take action until they do so.
"It is regrettable that news of such gravity has been received through the media," said Segura.
"We are still awaiting official confirmation. We have shown our frustration, for the slowness in receiving the official confirmation.
"We have formally requested notification.
"We have begun disciplinary proceedings, to be initiated once we receive official notification. Faced with such serious facts, the club will act harshly, but we will still make ourselves available to Dani Benitez.
"We are considering all the possibilities, ahead of any sanctions for the player.
"We will undertake a thorough study of the facts, before making any decisions.
"If this very serious situation is confirmed, the working relationship of the club and Benitez will obviously be affected.
"The club will support the player with all he needs on a personal level.
"Professionally, we must act with the utmost strictness. The club will remain available to help Dani Benitez on a human level. We will try to help him however we can."
