The 'Canyons' actress, who completed 90 days of court ordered treatment in rehab at the end of July, sparked concern after a photograph emerged appearing to show her reaching for a bottle of wine, amid rumors she recently fired her sober coach, but her father Michael Lohan has branded the speculation "ridiculous."
He told gossip website RadarOnline.com: "Oh my God. The story is ridiculous. First of all, I've never known Lindsay to ever, ever, ever have a glass of wine."
He added: "I've see and speak to Lindsay constantly and every time I do, she is of clear mind and by no means do I have any suspicion of her relapsing in any way."
Michael confirmed that Lindsay recently parted ways with her sober coach, but she has now hired a new person to help her stay on the wagon.
He said: "She has her life coach AJ with her and that's the same thing as a sober coach. Her sober coach from Cliffside lives in LA so they aren't living with her in New York City anymore.
"Maybe she goes out at night but who doesn't? She's up in the morning and she's doing the right thing."
A spokesperson for the actress also dismissed the rumors and said she "continues to succeed in her recovery."
The actress is preparing to fly to Los Angeles from New York City for meetings with film producers about several projects in the coming days.