Los Angelez - Kevin Costner is set to lead the tributes at Whitney Houston's funeral.
The 57-year-old actor - who starred alongside the late singer in 1992 movie The Bodyguard - will address mourners at her memorial service at the New Hope Baptist Church in Newark, New Jersey, on Saturday.
Whitney's godmother Aretha Franklin and music legend Stevie Wonder are set to perform at the funeral - which will be televised and streamed live on the internet - and her mentor Clive Davis will also deliver a eulogy.
The 79-year-old record executive had reportedly been paying Whitney's bills - but he is not planning to finance the funeral - and has been talking to her family "hourly" to help them deal with their grief.
A family source told People: "Clive has been a complete rock for her family this entire time. He's been with her since the beginning, and he's been everything to them. They're leaning on him for emotional support. He talks to them hourly, and he's a very big part in planning her funeral.
"Clive has been a constant presence for them. They're thanking God for Clive."
Oprah Winfrey has also been invited to the private funeral, but Whitney's ex-husband Bobby Brown is thought to have been told not to attend by the late pop star's mother Cissy as they blame him for the issues with drugs she had throughout her life. But he insisted earlier this week that he will be attending.
Whitney and Bobby's 18-year-old daughter Bobbi Kristina is set to see the I Will Always Love You hitmaker's body for the first time on Friday at the Whigham Funeral Home in Newark.
Whitney - who was found dead in the bathtub of her room at the Beverly Hilton hotel last Saturday - will be laid to rest next to her father, John Huston, at the Fairview Cemetery in Westfield, New Jersey, on Saturday.
Her official death certificate was released on Wednesday with the cause of her passing listed as "deferred", pending further investigation with the toxicology results expected in a few weeks.
It is widely believed a lethal combination of prescription drugs and alcohol was responsible for her passing at the age of 48.