An 18-year-old man has been charged with murder after the younger brother of a former Hells Angel bikie was stabbed to death in a popular Gold Coast dog park on Wednesday.

Key points: A group of young men was seen taking part in "altercations" on the street before the stabbing

A group of young men was seen taking part in "altercations" on the street before the stabbing An 18-year-old handed himself in to police, but he is reportedly not fully cooperating

An 18-year-old handed himself in to police, but he is reportedly not fully cooperating The brother of the 17-year-old victim is an ex-bikie, and his former neighbour's house was shot at in August

Harrison Geppert, 17, suffered critical injuries at Frascott Park in Varsity Lakes just after 5:30pm on Wednesday.

He was treated by paramedics but died at the scene.

Detective Acting Superintendent Brendan Smith said they have charged a man who surrendered himself to police last night.

"We will be alleging that the accused arrived near the park there where he got out of a vehicle and he stabbed the deceased in the back. Obviously as a result of that, he has died," he said.

"We will be further alleging that there were two vehicles in the street.

"We are seeking anyone in that immediate vicinity who may have seen two strange vehicles or a group [who] must have got out of one vehicle and commenced to assault the deceased.

Blood splatter markers are seen at a police crime scene at Frascott Park. ( AAP: Dave Hunt )

"Then the accused has got out of a second vehicle and stabbed him in the back while he was being assaulted by the first group of males.

"I can't stress enough that these people are all known to each other, it is a dispute between two groups of youths and the general public are not at risk.

"We know he [the victim] was with at least one person but we believe there may have been others."

Superintendent Smith said police hoped witnesses and possibly others involved to come forward.

"We would like those other males involved in the melee to come forward too because they may not be aware of what the final result of the attack was.

"It would appear that there were two separate incidents there, and the accused has come in after the first attack.

"They were there for other purposes from our investigations to date and it was just probably a chance discovery that the deceased and his friends were in the street at the same time.

"We think it is probably drug-related — it is an ongoing dispute between those two groups of young men."

Harrison's brother Ben Geppert has spoken about his grief on social media, vowing to avenge the death.

The little brother of former Hells Angel bikie Ben Geppert died on Wednesday evening. ( Instagram: bg_premium_apparel )

Last month, the house neighbouring Mr Geppert's former home was shot at, but no one was injured.

Mr Geppert, who appears to have the word "vendetta" tatooed on his face, said Harrison was a "true Geppert", and a "soldier".

"I wish I could of [sic] been there to help you, I would of [sic] never let this happen," he said.

"I won't stop till I sort this Harry I promise you.

"I love you more than anything regardless of the things that have gone on in our family your [sic] still my blood and I promise I won't rest till I have made this person pay!"

Police speak with a woman walking her dogs at the crime scene today. ( AAP: Dave Hunt )

Despite Mr Geppert's threat, Superintendent Smith is not concerned about a revenge attack.

"We're confident that the seriousness of the event last night will sink home today and it is very unlikely that there will be any revenge or retaliation amongst that group," he said.

"Obviously his brother is known to us, he is well known to the Gold Coast community.

A woman, Cathy, places flowers near where the teen was killed. ( AAP: Tim Marsden )

"We have no concerns that he is going to take the law into his own hands and I mean, if he even thinks about it, there is going to be consequences," Superintendent Smith said.

Superintendent Smith said there was no concern for safety for the wider community.

"It's not like we have got people running around attacking people at random," he said.

Witnesses say the park is usually quiet in the evening but popular during the day. ( AAP: Regi Varghese )

"So the people of the Gold Coast can be assured that it is safe to go to the dog parks and continue on with their daily lives."

A crime scene has been established and a homicide investigation is underway.

Police are also doorknocking neighbouring homes and appealing for witnesses, dashcam or CCTV.

Police and SES volunteers search for evidence at Frascott Park after the 17-year-old's death. ( AAP: Regi Varghese )

Jerome Javier arrived at the dog park shortly after the stabbing.

"So there was someone against the fence and a small crowd around him," he said.

"I just knew it was a teenager that got stabbed at that stage, and I think I stayed at the park until near the end."

Mr Jarvier said it took another few minutes for police and ambulance crews to arrive, but knew when they started CPR it was a bad sign.

Homicide investigators scoured the scene overnight. ( AAP: Regi Varghese )

"It's very scary, because I come here every day, morning and night," he said.

"I usually walk my dog around the park at night because there's no one else.

"I wouldn't think this could happen during the day in a park where there's maybe 30 kids playing, a hundred metres away from the scene."