Officers were called to reports a child had been injured in Carr Lane, Milnrow, at around 1.15pm on Sunday (May 15).
A three-year-old boy, who has been formally identified as Daniel John Twigg, was taken to hospital where he died a short time later.
Enquiries established Daniel was with a number of dogs in an outdoor area surrounding his home before he was discovered with serious injuries, police said
Police confirmed several dogs were seized, and one Cane Corso was “humanely destroyed”.
A 48-year-old man was arrested under the Dangerous Dogs Act 1991 after handing himself in to custody.
He remained in custody for questioning on Tuesday, May 17.
Det Chief Insp Gina Brennand, of GMP’s Major Incident Team, said: “I send my condolences to Daniel’s loved ones.
"This is a heart-breaking time for them, specially trained colleagues are supporting them.”
She added: “Though a man is in custody, our investigation is very much ongoing to establish the full circumstances surrounding this incident and ensure any criminal offences in relation to Sunday’s incident are identified and prosecutions sought.“Meanwhile, officers are also reviewing other incidents of note. Due to previous contact, GMP’s Professional Standards Branch has referred the incident for review by the Independent Office for Police Conduct.
“We understand that this incident has had an impact on the community but we ask members of the public and the media to refrain from speculating whilst we complete our investigation and any subsequent proceedings are concluded.”