The father of the murdered 16-year-old schoolgirl Larissa Beilby says her death hit him “like a sledgehammer”.

Peter Beilby has told the Nine Network he was out searching the streets six days ago when he got the news his daughter’s body had been found in a barrel in the back of a ute south of Brisbane.

“It was like a sledgehammer hitting me, I was just broken,” he said. “I couldn’t put it into words, it was like a physical thing.”

It is the first time Larissa’s father has spoken publicly about his daughter’s death, appearing at a Brisbane graffiti wall on Monday night where friends of his daughter have painted a mural in her honour.

Beilby laid a rose at the site, saying he was “still processing” what had happened.

“It breaks my heart thinking how she must have been feeling, like, when she knew what was going on,” he said. “I’m picking the things that I process but I just want to do Larissa honour now, bury her and put her to rest.

“We’re going to cremate her and then I’m going to take her back to Adelaide and bury her with her mum.”

Friends and family of Larissa want to get away from the image of her as the “girl in the barrel” and remember the “happy, cheeky adventurous girl” they knew as “Riss”.

Zlatko Sikorsky, 34, has been charged with murder, torture, deprivation of liberty and interfering with a corpse over Larissa’s death.

He was arrested last Saturday after a 28-hour standoff with police on the Sunshine Coast. However, his lawyer on Monday claimed her death had been due to “misadventure” and they would be fighting some of the charges.

Detectives investigating Larissa’s death have meanwhile put out a fresh call for information about a vehicle of interest.

They are searching for a 2014 silver Holden Commodore sedan with a sunroof and Queensland registration plates 966 WKB which may have since been removed or replaced.