Kurt Zouma has been fined £250,000 and has had his cats taken away from him by the RSPCA after he was filmed kicking and slapping them.
A statement from the animal welfare charity on Wednesday read: "Two cats are now in RSPCA care. Our priority is and has always been the well-being of these cats.
"The cats have been taken for a check-up at the vets and will remain in our care while the investigation continues.
"We're grateful to everyone who expressed their concern for these cats.
"We were dealing with this issue before the video went viral online and are leading the investigation. We continue to investigate so we cannot comment further at this time."
Former Chelsea defender Zouma issued an apology after the video, obtained by The Sun, was shared by his brother Yoan on Snapchat and went viral.
Zouma has now been fined £250,000 by West Ham, which equates to two weeks wages for the centre-back. The money will be paid to animal welfare charities.
Essex Police confirmed it was looking into the video on Tuesday before the RSPCA intervened and confiscated the animals.
West Ham, meanwhile, carried out their own internal investigation into the incident, which they strongly condemned in a statement on Monday evening.
The club released a second statement on Wednesday, reading: "West Ham United can confirm that the club is supporting an RSPCA investigation into the actions of Kurt Zouma in the video circulated online this week.
"Kurt and the club are cooperating fully with the investigation and the player has willingly complied with the steps taken in the initial stage of the process, including delivering his family's two cats to the RSPCA for assessment.
"Kurt is extremely remorseful and, like everyone at the club, fully understands the depth of feeling surrounding the incident and the need for action to be taken.
"Separate to the RSPCA's investigation and pending further sanction once the outcome of that process is determined, West Ham United can confirm that Kurt Zouma has been fined the maximum amount possible following his actions in the video that circulated.
"The player has immediately accepted the fine, which will be donated to animal welfare charities. West Ham United would like to reiterate our condemnation of Kurt's actions and make it clear that the matter continues to be handled with the utmost seriousness.
"However, we believe it is now important to allow the RSPCA to conduct their investigation in a fair and thorough manner and will be making no further comment at this stage."
West Ham boss David Moyes came under fire for naming Zouma in his starting XI for his side's 1-0 win over Watford in the aftermath of the incident.
He said: "The club will sort the other side of it out and I will look after the football side.
"My feeling was Kurt has apologised and I understand that a lot of people will not just accept an apology I understand that.
"But to me, he came out and he said that very honestly and as I said before I had to do my job then and that was to pick the best team I possibly could."
