Lindsay Lohan's father has accused his fiancee of being a liar with a drinking problem.

Michael Lohan has hit back at Kate Major - who told police officers he threatened to kill her with a knife at their home in Florida on Monday night, after they got into a heated fight that led her to blast him on Twitter - and insists he was only trying to protect their 13-month-old son, Landon.

"My son Landon and nanny are with me. Kate's been having a lot of problems lately with her drinking and pill use and after catching her drinking again tonight, I threatened to take my son away from her, she started this whole thing on Twitter," the 53-year-old told gossip website RumorFix.com.

Michael, who denies threatening Kate in anyway, claims he called the police to prove Kate "lied" about the incident on Twitter: "I actually had my neighbor over who is a sheriff, but after hearing of Kate's sick tweets, I called the police to prove she lied. Soon after they came, they realized she lied they left."

According to the police report, obtained by TMZ.com, Kate claimed Michael falsely accused her of drinking around their baby before grabbing a knife and threatening to kill her with it. She said she locked herself in a bedroom to get away from him. But the 30-year-old, who denied Michael's previous claims that she was hospitalized after attempting to harm herself on Saturday, hinted she is eager to move past the incident and tweeted today, "I love Landon & nothing will ever change that or take that from me!!!!" She added, "I should not have tweeted anything. This has all turned into a whirlwind. I'm sorry."

(FYI - You can also follow VIP Breakdown on Twitter.)