Speaking before the Olympics, Daley revealed his father “gave me all the inspiration that I’ve needed”.
The 18-year-old told the BBC: “Winning a medal would make all the struggles that I’ve had worthwhile. It’s been my dream since a very young age to compete at an Olympics.
“I’m doing it for myself and my dad. It was both our dreams from a very young age.
“I always wanted to do it and Dad was so supportive of everything.
“It would make it extra special to do it for him.”
When news of the insensitive tweet spread, Rileyy69 attempted to apologise.
He tweeted: “@TomDaley1994 I’m sorry mate i just wanted you to win cause its the olympics I’m just annoyed we didn’t win I’m sorry tom accept my apology.”
He later added: “please i don’t want to be hated I’m just sorry you didn’t win i was rooting for you pal to do britain all proud just so upset.”
The apologetic messages were interspersed with a stream of expletives and further abuse to other users.
Dorset Police yesterday confirmed it was investigating the incident.
A spokeswoman said: “Regarding tweets to @tomdaley1994 - we are aware of the issue and we are actively looking into it.”
She added today: “A 17-year-old man was arrested by Dorset Police officers in the early hours this morning at a guesthouse in the Weymouth area on suspicion of malicious communications.
“He is currently helping police with their inquiries.”
Andy Hunt, CEO of the British Olympic Association, told the BBC he has spoken to Tom Daley about the incident.
“He’s not affected, the team are focused on performance,” he said.
guys, please stop arresting people for twitter insults. It’s starting to get ridiculous.