Police said the 45-year-old woman hailed from Comilla district of Bangladesh and was arrested from Jagiroad area of central Assam's Morigaon district.
She had illegally crossed the border about two weeks ago, the police said.
She was involved in several cheating cases at Dharamtul and Jagiroad areas and duped women there of their gold ornaments on the excuse of polishing them.
The woman was being interrogated, the police added.