New York Consolidated Laws, Real Property Actions and Proceedings Law - RPA § 541. Adverse possession, how affected by relation of tenants in common

Where the relation of tenants in common has existed, the occupancy of one tenant, personally or by his servant or by his tenant, is deemed to have been the possession of the other, notwithstanding that the tenant so occupying the premises has acquired another title or has claimed to hold adversely to the other.  But this presumption shall cease after the expiration of ten years of continuous exclusive occupancy by such tenant, personally or by his servant or by his tenant, or immediately upon an ouster by one tenant of the other and such occupying tenant may then commence to hold adversely to his cotenant.