Bachelorette Star Kasey Kahl Arrested

Law enforcement sources tell TMZ ... Kahl -- who recently appeared on "Bachelor Pad" -- was allegedly involved in an incident at a place called Club Habanos. So far, it's unclear exactly what Kahl is accused of doing wrong.

Kahl was booked at a nearby police station -- where he took one of the prettiest mug shots we've ever seen and was released a few hours later.

Kahl just finished taping the inaugural season of VH1's upcoming "Relationship Rehab" with former GF Vienna Girardi.