Klaus Stoehlker, who has advised Blatter in the past, told Sky News that the committee made the ruling in light of further investigations by the Swiss authorities.
He said that the Swiss attorney general's investigation was "pending" and so far no negative findings have been made against the Fifa boss.
Blatter faces criminal charges around a payment made to Uefa president, and his potential successor, Michel Platini. He's also attracted attention for an "unfavourable" contract signed with the Carribean Football Union while disgraced former president Jack Warner was in charge.
Blatter, who has been at the helm of Fifa since 1998, and Platini have denied any wrongdoing.
A final decision is likely to be made on Thursday, according to BBC Sport.
Stoehlker told BBC Sport: "The news was communicated to the president this afternoon. He is calm. Remember he is the father of the ethics committee."
"This is provisional for 90 days but he is not actually suspended. The committee has not yet made a decision and their meetings continue."