The leaked clip, which was originally broadcast by Argentine TV programme Nosotros al Mediodia, allegedly shows Maradona, who appears to be in a drunken state, throw a phone towards Oliva before approaching her.
According to the New York Daily News, the video, which is believed to have been filmed by Oliva, cuts out after Maradona's former fiancee yelled: "Stop! Stop! Stop hitting me."
In response to the allegations, Maradona told Argentine journalist Marina Calabro in a series of text messages: "Yes, I threw the phone but I swear to God that I have never raised my hand against a women.
"The episode started and ended like that. I admit to throwing the phone, but nothing else."
The couple split up earlier this year.