"I'm more amused than I've ever dreamed a person could be and look forward very much to how hilarious it will be watching him trying to prove me wrong," O'Connor, 49, wrote. "I'm also very happy to notice that the DEA have taken me seriously enough to be thoroughly questioning all of Prince's friends and aides from the last thirty years as to his KNOWN history of hard drug use and where he obtained his drugs."
"I do not like drugs killing musicians," the post continued. "And I do not like Arsenio Hall. He can suck my d**k. That is if he isn't too busy sucking someone else's d**k : )."
Hall filed the lawsuit after O'Connor posted a lengthy message via Facebook on Monday about his relationship with Prince, who was found dead in an elevator at his Paisley Park estate in Chanhassen, Minnesota, last month. The Irish singer's original post read:
"Two words for the DEA investigating where prince got his drugs over the decades.... Arsenio Hall (AKA Prince's and Eddie Murphy's b*tch). Anyone imagining prince was not a long time hard drug user is living in cloud cuckoo land. Arsenio I've reported you to the Carver County Sheriff's office. Expect their call. They are aware you spiked me years ago at Eddie Murphy's house. You best get tidying your man cave."
In court documents obtained by ET earlier this week, Hall's legal team accused O'Connor of creating "despicable, fabricated lies."
"Desperate, attention-seeker Sinead O'Connor has maliciously published outlandish defamatory lies about comedian Arsenio Hall, falsely accusing him of supplying illegal 'hard drugs' 'over the decades' to the recently deceased musical artist, Prince, and of spiking her with drugs once years ago."
As ET previously reported, the 60-year-old comedian's attorneys also claim that O'Connor's "wild and false accusations" caused substantial harm to Hall's reputation.
"O'Connor is now known perhaps as much for her bizarre, unhinged internet rants as for her music," Hall's legal team wrote. "Among other things, O'Connor has repeatedly admitted that she actually detested Prince during his life, that she had a feud with Prince, and that she once had a violent fistfight with Prince and spat on him repeatedly after she told Prince 'to go f**k himself."
ET reached out to Arsenio Hall's reps, who had no further comment on the situation.