An anonymous post circulated around the internet during the ITV show's fifth series that 12-year-old Parke had a pre-existing professional relationship with Simon Cowell's entertainment company Syco/Sony Music.
The claim was adamantly denied by Cowell's team, who threatened to take legal action against the mystery author and worked with the police to uncover their identity.
An individual claiming to be behind the Britain's Got Talent post later apologised for their actions, and a Scotland Yard spokesperson today revealed that a 52-year-old man had been officially cautioned.
"We can confirm that a 52-year-old man has accepted a caution under the Malicious Communications Act. There is no further police action," the representative said.
"A man has now admitted responsibility for the wholly untrue blogs relating to Ronan Parke and the false allegations against Britain's Got Talent, Sony Music and Syco," a Sony Music spokesperson added to The Guardian.
"He has admitted he has absolutely no connection with Ronan Parke, Sony Music, Syco, or Britain's Got Talent. He has apologised both via the police and directly to those involved and the matter will not be taken further."
Sony Music chairman Ged Doherty also commented on the resolution of the scandal, saying: "I'd like to thank the Metropolitan Police for their assistance in bringing closure to this matter."
Cowell previously said that he felt "sick" over the "poisonous" and "malicious" email.
Parke eventually finished runner-up to singer Jai McDowall when Britain's Got Talent concluded in June.
The youngster has been tipped to make around £1.5m by Christmas.
Watch Ronan Parke perform Kelly Clarkson's 'Because Of You' in the Britain's Got Talent final below: