Okla. Stat. tit. 12, § 2802
Hearsay is not admissible except as otherwise provided by an act of the Legislature.
Laws 1978, SB 276, c. 285, § 802, eff. October 1, 1978; Amended by Laws 2002, HB 1939, c. 468, § 58, eff. November 1, 2002 ( superseded document available).