United Kingdom, June 24 -- Whitney Houston's estate is furious about Oprah Winfrey's claim that she fell from the stage while performing on her talk show after she allegedly relapsed into drug use.

They confirmed that the singer tumbled over when she appeared on the 72-year-old media mogul's talk show in 2009, but vehemently denied it being linked to her substance abuse, insisting it happened during a dark sound check.

Pat Houston, who runs Whitney's estate, told TMZ: "Whitney absolutely fell off the stage, but it was during a sound check, and it was due to the darkness of the area and her unfamiliarity with the stage. She was absolutely not high."

While she acknowledged the I Will Always Love You hitmaker's long battle with addiction,...