MELBOURNE (AFP) - Hundreds of mourners packed a Melbourne church on Wednesday to bid farewell to an Australian baseball player killed by two teenagers in a random Oklahoma shooting that triggered a race debate.

Mr Chris Lane, 22, was gunned down in the small town of Duncan by a pair of "bored" black teens, aged 15 and 16, as he was out jogging on August 16, reviving debate sparked by the death of black teenager Trayvon Martin in Florida last year.

Mr Lane was in the United States on a baseball scholarship and scores of his Essendon baseball clubmates formed a guard of honour outside St Therese's Catholic church for his funeral, where the steps overflowed with floral tributes.

Almost 1,000 people crammed into the church to pay tribute to Mr Lane, with Father Joe Giacobbe saying in 40 years he had never "seen this church as full as it is today".

Mr Lane's father Peter spoke of a young man who seized life "with both hands and ran with it", and said his son would not have known what to make of the "fuss" over his senseless murder thousands of kilometres away from home.

"When someone as young as Chris loses their life it's always a tragedy, but when someone's life is lost for no purpose or reason, it makes it that much harder to accept," he said.

"What happened to Chris is just not fair, but hanging on to it will not help."

His eldest sister Andrea remembered Mr Lane as a compassionate and just person who was "always helping out the underdog or anyone who was disenfranchised".

"You are braver than you believe, stronger than you seem and smarter than you think," she said tearfully, flanked by Mr Lane's other two sisters Jennifer and Erin.

Mr Lane's American girlfriend Sarah Harper draped an Oklahoma flag over the coffin. "I Believe I Can Fly" and "If I Die Young" were among the song choices.

Accompanied by her family, Ms Harper did not speak at the service but Peter Lane thanked them for travelling to Australia and "accepting that funny-talking kid as one of your own".

James Edwards, 15, and Chancey Luna, 16, have been charged with Lane's murder and face the death penalty if convicted.

Prosecutors have said there is no evidence that the killing was racially motivated, despite Edwards posting remarks about his hatred of white people on social media earlier this year.

According to police the pair were "bored and wanted to see someone die".

A third teenager, Michael Dewayne Jones, 17, has been charged with use of a vehicle in the discharge of a weapon and acting as an accessory after the fact.

The case revived a race debate in the United States sparked by the 2012 shooting of black teenager Trayvon Martin by George Zimmerman in a gated community in Florida.

Mr Zimmerman, who said he acted in self-defence, was acquitted in July, prompting vigils and protests across the United States.