Kim Zolciak‘s daughter, Ariana, denied drinking and driving after crashing into another vehicle … but cops say she did admit to vaping the night before.

According to the police report, obtained by TMZ, the 20-year-old reality star denied drinking any alcohol during her DUI bust over the weekend. Officers informed Zolciak they could smell alcohol on her breath and she allegedly stated the smell could be coming from her clothing.

Cops say Ariana admitted she “smoked a THC vape pen the night before but did not drink.” During the back and forth, she maintained she had not been drinking — but cops say she had a “noticeable sway” during field sobriety tests.

TMZ broke the story — Ariana was arrested in Forsyth County, GA, Saturday, and booked on 3 charges … misdemeanor DUI, misdemeanor improper/erratic lane change, and misdemeanor underage alcohol possession/purchase of alcohol.

The whole thing happened after she allegedly hit another vehicle.

Ariana’s attorney tells us, “Despite Ariana’s constant invocation that she was upset and anxious from the minor accident, the officer incorrectly concluded she was impaired by alcohol. That was not the case. She wholly denies these allegations and intends to fight these charges because she is not guilty of them.”