The untimely passing of Tammy Wynette will be the focus of an upcoming episode of 'The Will: Family Secrets Revealed,' a reality documentary series that discloses ongoing family turmoil that surrounds the final requests of their deceased celebrity loved ones.

In the episode, producers will spotlight the mysterious exclusion of Wynette's four daughters from her will, which included the singer's extensive music rights portfolio and two $1-million life insurance policies. Discrepancies regarding Wynette's death arose after the siblings launched a $50 million wrongful death lawsuit against their mother's physician, and stepfather, George Richey, who became the beneficiary to Wynette's estate.

Born Virginia Wynette Pugh, the Mississippi native rose to immediate country music fame in 1967 with her No. 1 hit 'I Don't Wanna Play House,' following up her first hit with a string of six chart-topping singles -- earning 20 No. 1s in total before her passing in 1998. Often referred to as the 'First Lady of Country Music,' Wynette is most recognized by her classic 'Stand By Your Man,' one of the most-performed songs in the history of country music.

Though Wynette's life was plagued by persistent illness, the singer passed away unexpectedly while resting on her couch on April 6, 1998 at the age of 55. A blood clot was initially to blame for Wynette's passing, but her body was later exhumed for further investigation, and it was revealed the singer had passed from an irregular heartbeat. Richey was dropped from the aforementioned lawsuit in May 1999.

Wynette's episode of 'The Will: Family Secrets Revealed' will kick off Season 3 of the popular Investigation Discovery series. Fans can learn more about the family drama by tuning in on Oct. 18 at 9PM ET.