Vertex count is 30 times higher in Unity

Hi, I have a simple scene in Unity, with some models, a directional light and a reflection probe. Maya says that there are about 24k verts. We have our own engine, and it says 35k verts (it takes into account the uv seams and hard edges). But in Unity, the stats window shows about 1 million verts... that's 30 times the real vertex count! If I turn off the light, it goes down to 500k verts... it's still 15 times the real vertex count. The scene is composed of 3 models for the background and one for the floor (a simple plane with some polygons to make variations) Why is this happenning? Thanks!