The Brazilian government says it wants a rigorous investigation into the death of a 21-year-old student who was tasered by police in Sydney.

Roberto Laudisio Curti died shortly before sunrise on Sunday morning after he had been sprayed with capsicum spray and tasered.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 2 minutes 55 seconds 2 m 55 s Family speaks out on Taser death Download 1.3 MB

The Brazilian student had been living with his sister and her Australian husband in Sydney since last winter, while studying English and playing soccer.

His uncle flew into Sydney from Sao Paulo last night and the family has engaged a lawyer to help them find answers.

He will help Mr Laudisio Curti's sister return the body to Brazil.

"We are still coming to terms with the sudden and unexpected loss of our beloved Roberto," the family said in a statement.

"He was a young man who was much loved by his family and his many friends, both in Australia and Brazil, and had a promising future ahead of him."

The student's parents died of cancer recently.

The Brazilian foreign ministry has now ordered its consulate in Sydney to assist the dead man's family and "obtain the necessary clarifications from the Australian authorities".

The ministry says it is confident Australian authorities will conduct an investigation "with the necessary rigour".

Police officers said Mr Laudisio Curti was resisting arrest, but detectives are looking into whether guidelines were breached by tasering Mr Laudisio Curti as he ran away.

Stun guns are only meant to be deployed by officers to protect people from violence.

There have been reports that Mr Laudisio Curti was tasered by up to three officers.

Police had been investigating the theft of a packet of biscuits from a nearby convenience store.

His uncle has been quoted in the media rejecting the notion his nephew would have stolen biscuits, and saying Mr Laudisio Curti had been given a clean bill of health.

Roberto Laudisio Curti had been living in Sydney with his sister since last winter ( Globo )

The New South Wales Government yesterday announced the state's ombudsman would oversee the investigation into Mr Laudisio Curti's death.

Ombudsman Bruce Barbour says the case is of significant public interest and requires more careful scrutiny than most.

Premier Barry O'Farrell has reassured the family that the investigation will be thorough and transparent.

"I say to any country and to the citizens of any country, Australian law is rigorous, Australian law is independent of government interference and Australian law, 99.99 per cent of the time, gets it absolutely right," Mr O'Farrell said.

"I give them the assurances that every Australian citizen has, which is that there will be a coronial inquiry, there's an ombudsman's inquiry into this matter.

"That will be conducted according to Australian law, according to the independence and transparency that normally comes with those investigations."

The president of the Australia-Brazil Chamber of Commerce, Cristina Talacko, told the ABC's AM program she knows the family.

"This is a very good family from Brazil. This boy was just visiting and studying English here in Australia and living with his sister," she said.

"It's just a very sad incident, one of these things that is a one in a million situation that unfortunately happened to this particular family and the Brazilian community is very saddened with the news."

Ms Talacko says almost 20,000 Brazilians comes to study in Australia each year.

"We do hope that this case will not shake the relationship in any way. All in all, the relationship has been very good," She said.

"At the moment there might be some issues because the case is so new and young, but I believe that long-term there won't be any damage to the relationship, especially if the Australian police conduct themselves in a very transparent and fast way with this investigation."

More than 1,300 people have indicated online they will attend a protest outside the Australian consulate in Sao Paulo this week in memory of Mr Laudisio Curti.

The group plans to leave a packet of biscuits out the front.