A NSW police officer used "excessive and unlawful" force when he tackled and repeatedly punched a 17-year-old Aboriginal boy, the state's police watchdog has alleged.

The Law Enforcement Conduct Commission (LECC) handed down their findings on Monday, following an investigation - known as Operation Potosinto - into the officers use of force, which saw the "slightly built" boy (known as ZDP in the report) dragged in handcuffs along the floor of a Western Sydney Local Health District hospital that he was trying to escape from.

The commission called for disciplinary action against the "considerably taller, heavier and stronger" officer (known as JGH in the report) who was involved in the November 2020 arrest.

Led by Commissioner Anina Johnson, it said the teenager was taken to hospital for assessment on 29 November, before he tried to escape.

Witnesses, including hospital staff, told the commission they saw the teenager being tackled to the ground, punched three times in the head and then dragged him "6 or 7 metres" along the ground, whilst in handcuffs.

"After the 17-year-old was apprehended and brought under control, the police officer without justification punched the young person twice in the head before dragging him along a hospital floor, and then not adequately recording the use of force," the report said.

"The Commission is also satisfied that Officer JGH did not make any attempt to get ZDP to stand up. Rather he dragged him along the ground. This was completely unreasonable.

"The commission recommends that the commissioner of police take disciplinary action against (the) officer."

A hospital witness said that JGH "made no effort to first stand him (ZDP) up."

"(He was) not resisting, kicking or thrashing but was immobile," they said.

"Dragging anyone, let alone a youth, by his handcuffs along the floor for 6 or 7 metres in front of hospital staff, patients and family members, is degrading. This conduct clearly upset hospital staff and at least 1 patient and a member of his family," the report said.

Commissioner Johnson said the event had a significant impact on hospital staff.

"Experienced hospital staff were shocked at what they saw in the emergency department that day," she said

One nurse - a veteran of 25 years - said the event left her " traumatised and disgusted" with the actions of JGH.

"… something you never forget. I'm never going to forget… it's just - it's not very good," she said in her evidence to the commission."

The report found that the first punch thrown by the officer was "reasonable" in order to gain control of the situation but that "the second and third punches, and the dragging of ZDP by the handcuffs amount to serious misconduct".

One officer denied that JGH had dragged the boy, but in the report it stated: "The Commission prefers the evidence of the hospital staff".

Both JGH and another officer, ZBD, said they performed guard duties before and after the incident and it was hard to recall the specifics of the evening of 29 November. The commission argued "neither had made notes of the incident in their notebooks," and the "(Computerised Operational Policing System) COPS entry is vague and of little help".

The report stated that the officer's only entry into his notebook was a reference to the amount and the vehicle they had been working in. He recorded in the COPS database after the incident that "the accused attempted to resist police custody," and noted "police were required to use force to restrain the accused".

The commission took a dim view of the lack of information, arguing that it "fell short of the standard set by the NSWPF Crime Recording Standard".

"This investigation is yet another example of the failure by police to record any, or sufficient information, and the consequences that may result from that failure," the report said.

"He (JGH) had exercised a police power, but did not provide sufficient details to justify that use. Officer JGH failed to make an adequate record even though he was already on notice that his actions were likely to be subject to external scrutiny."

In a statement to National Indigenous Times, the NSW Police acknowledged that the officer was still employed.

"The NSW Police Force notes the release of the Law Enforcement Conduct Commission (LECC) report in relation to Operation Potosi, and that LECC has recommended the incident be referred to the DPP," it said in a statement.

"NSW Police will await advice from the DPP. Police are considering the recommendations put forward by LECC."

The LECC noted that in February, and again in July, it had recommended the NSW police force improve instructions it provides officers in regard to the recording of use of force.

The NSW police has been criticised for its handling and behaviour towards Indigenous people in several incidents.

In July, the LECC found a NSW Police Officer engaged in serious misconduct after he threw a torch at a 16‑year‑old Aboriginal man striking him on the back of the head causing an injury in the early hours of 21 November 2020.

The Commission also found the officer's failure to switch on his body worn camera, as well as not reporting his use of force, was serious misconduct.

In May, a NSW police officer was found guilty of occasioning actual bodily harm after arresting an Indigenous boy in 2020.

Constable Barlow held the teen's arms behind his back and used a 'leg sweep' motion to slam him to the ground, which was caught on camera and contradicted a statement given by Mr Barlow on the incident.