Sun columnist Kelvin MacKenzie is to be questioned over comments he made about Everton footballer Ross Barkley, according to Liverpool's mayor.
In an article, the paper's former editor compared the Everton midfielder, who has a grandfather born in Nigeria, to a "gorilla".
Liverpool mayor Joe Anderson said it was a "racial slur... and something we won't tolerate".
Mr MacKenzie has been approached for a comment but is currently on holiday.
Previously, he said in a statement it was "beyond parody" to describe his column as "racist".
A spokesman for Merseyside Police said their investigation was on-going and they would be speaking to relevant witnesses.
In his column in The Sun, published on 14 April, Mr MacKenzie said looking at Barkley's eyes gave him a "similar feeling when seeing a gorilla at the zoo".
He also said that men with similar "pay packets" in Liverpool are "drug dealers" and in prison.
Alongside the article, The Sun published an image of a gorilla next to a picture of the midfielder who was attacked in a Liverpool bar.
'Wrong and unfunny'
The Sun, which suspended its former editor, apologised "for the offence caused" adding it was "unaware of Barkley's heritage".
"The views expressed by Kelvin MacKenzie about the people of Liverpool were wrong, unfunny and are not the view of the paper.
"Mr MacKenzie is currently on holiday and the matter will be fully investigated on his return."
Liverpool mayor Joe Anderson said he made a complaint to police and reported the article to the Independent Press Standards Organisation.
In comments to Liverpool City Council's cabinet earlier, Mr Anderson said "Merseyside police are investigating and will be interviewing the person concerned.
"This has been a continuous attack from this individual and a racial slur on one of the sons of this city and something we won't tolerate."