Tara Reid Alleged Bar-Drugging Case Officially Closed, Illinois Cops Say

Tara Reid's allegations of drugging aren't necessarily false, but right now cops say their investigation's hit a dead end ... and they don't have any evidence to support the claims.

The Rosemont Police Department in Illinois tells TMZ ... no new evidence in the case has come to light, and the case is now closed.

We're told doctors didn't take chemical tests when Tara was rushed to a Chicago-area hospital last month ... so, they won't know exactly what -- if anything -- was in Reid's system at the time.

RPD adds, "We are not saying that [Tara's] claims are false, however at this time we do not have evidence to support it and there is nothing further on our end to investigate. Should additional evidence of a crime be brought forward, we will reopen the case and investigate accordingly."

As you know ... Tara was rushed to the hospital from a hotel near Chicago's O'Hare Airport after an employee called 911 to report a "really inebriated" guest who was having trouble staying awake.

Reid told us she only had one drink at the hotel bar that evening ... though after she was served, she went outside to smoke a cigarette. When she came back, she said a napkin had been placed over the top of her glass of wine -- though she decided to drink it anyway. The next thing Reid knew, she was in a local hospital receiving treatment.

We obtained security video of Reid drinking at the bar ... during which time it appears she has two drinks. Tara has maintained she doesn't remember anything after the first -- and she's accused the media of twisting her words and attacking her even though she was the alleged victim.