Samuel Worthy, 21, has been accused of lying under oath to reduce his culpability in the killing of 20-year-old Joshua Kane at Mount Eccles National Park in January 2016.

He and two others have pleaded guilty to Mr Kane's murder.

"I suggest to you that you wielded the machete that day," crown prosecutor Justin Lewis said in the Victorian Supreme Court on Friday.

"No, I didn't," Worthy replied.

The victim was left for dead in the bush and Worthy, Lanie Snell, 35, and Stuart Campbell, 20, have since pleaded pleaded guilty to the machete murder.

Snell had the motive as she was angry at Mr Kane for calling her son "lazy", the court has been told previously.

The three co-accused collected the victim from his home at Hamilton caravan park under the guise of going for a hike.

Armed with a machete, knives and a bottle of bleach, they drove to Mt Eccles and embarked on a track to Lake Surprise.

When it started to get dark, they turned around to walk back to the car, and Mr Kane was hacked to death.

Snell was jailed for 18 years in June by a judge who said she orchestrated the killing and Worthy wielded the weapon.

But Worthy, who is awaiting sentencing, tells a different story.

"I stopped to light a cigarette and that's when Lanie (Snell) rushed past me and struck Josh in the head," he told his plea hearing.

"Josh yelled out, 'F***, I'm bleeding, what did you hit me with?'

"Lanie said nothing. She just continued to hit him with the machete."

Worthy said he walked off in shock but soon returned, coming across Mr Kane slumped against a tree.

Worthy said he thought the group would only "hurt" Mr Kane, who was his "best friend".

"It was put as pushing him in the water and leaving him to walk back to town," he said.

But the prosecutor suggested this was untrue, and Worthy was lying in court.

"It's an effort to minimise your responsibility for the murder of Joshua Kane," Mr Lewis said.

Worthy will be sentenced at a later date.

- AAP