After the Spain international scored his third goal of the season in a 2-1 victory over Leicester City at the King Power Stadium, sections of the Chelsea following could be heard singing: "Alvaro, Alvaro. He comes from Madrid, he hates the fucking Yids."
Ahead of the Blues' Champions League return, Atkins told reporters: "We made an initial statement after the game the other night and we are happy to repeat but also make clear that Chelsea Football Club finds all forms of discrimination abhorrent, and the language used in that song the other night we find totally unacceptable
"People that use this kind of language against others always try and argue a grey area. There is no grey area. That language used was anti-Semitic and we have a zero tolerance policy towards it.
"If there is there is evidence that season ticket holders or members took part in that and take part in it in the future then we will take the strongest possible action against them which includes bans.
"People should know that the police will be investigating and they will investigate all future such episodes, and we will support the police in anything that they do, assist their enquiries, and we will also support criminal prosecution of such behaviour and activity. We must be clear on this because it has to stop."
Meanwhile, the West London outfit are preparing for Tuesday's Champions League group match against Qarabag FK.