Kevin Costner will deliver a speech at Whitney Houston's funeral.

The actor, who co-starred alongside Whitney in the 1992 film The Bodyguard, will join a handful of celebrities who are set to attend the service this weekend.

Stevie Wonder and Aretha Franklin will sing at the memorial and Whitney's long-time producer Clive Davis is also set to speak.

Whitney's kin is suffering immensely from the iconic singer's passing.

"Whitney's family is devastated, but they're getting through it," a source told People magazine.

Clive, who is reportedly also deep in mourning for the loss of Whitney, is proving to be a strong emotional support for the singer's loved ones in their time of grief.

"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," the source continued. "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."

Although it was rumoured that Whitney's ex-husband Bobby Brown was not invited to her funeral, insiders confirm that he will in fact attend the service.

"He is not being banned. That's completely untrue," the source revealed. "Bobby will be there at the funeral to support his [and Houston's] daughter [Bobbi Kristina Brown, 18]. There was some talk... some people were angry at him, but that's just grief. He will be there."

The memorial service will take place in Newark, New Jersey at the New Hope Baptist Church, where Whitney first sang in the choir, this Saturday at noon.

Around 1,500 people have been invited and it has been reported that the icon's private funeral will be broadcast live on television so fans can also watch the service.