The 29-year-old is believed to have made the remarks on Tuesday night over the number of black players that the North East club have in their squad.
"We have received a report of racist comments made on Twitter," said a Northumbria Police spokesman.
"We take all reports of racist abuse very seriously and inquiries are being conducted.
"A 29-year-old man has been arrested in connection with the incident and is currently in custody."
The Magpies confirmed the £9m capture of Cisse yesterday.