A murder warrant has been issued for a teenager while images have been released of a man “critical” to investigations into a fatal shooting.

Abdullah Bahsa, 38, and another man were allegedly assaulted by a group of five “heavyset” men dressed in black at an apartment on Shale Street in Lidcombe, in Western Sydney, about 4am on March 16.

Bahsa was shot in the lower abdomen and rushed to Westmead Hospital, where he later died.

The second victim was taken to the same hospital with non-life-threatening injuries.

More than a week after the alleged attack, police released images of a man they believe may assist with their investigation into the shooting.

The pictured man is of Pacific Islander or Maori appearance, aged in his 20s or early 30s, with a black beard and moustache.

The image shows him wearing a black zip-up hoodie over a black cap.

Superintendent Robert Toynton said investigators consider the man “critical” to ongoing inquiries.

“That male can greatly assist us in our inquiries,” Superintendent Robert Toynton said.

“We’re seeking assistance from the community to help ID him.

“That person has family, friends … they’re going to to know who this person is.”

Toynton added he is “linked to a very serious crime” and anyone who sees him should contact police.

The unknown man is one of six people police have identified and want to speak to, but there are a “number of others” who are yet to be identified.

Toynton revealed police have issued a warrant for an 18-year-old Henrick Becker, also known as Henry, wanted for alleged murder.

“He is known to frequent the Sydney Olympic Park area, Castle Hill area and Artarmon area,” he said.

“I strongly encourage him to hand himself in to his nearest police station but, if anyone knows his whereabouts, please get in touch with the police.”

In the 10 days since the initial attacks, police arrested four men, aged 19, 21, 22 and 26, who have been charged with offences including murder.

They remain before the courts.