Rajwinder Singh has been the target of an online hate campaign after he was wrongfully identified and accused of sexual abuse.

An Indian student wrongly accused online of sexual abuse wants justice after receiving death threats, and becoming too scared to go outside.

A photo of Rajwinder Singh riding a Christchurch bus went viral after it was uploaded to Facebook in January with accompanying message accusing him of molesting someone.

"Please be aware of this guy," the message said.

"He molested a friend of mine a while back ad [sic] was let away with 'a warning'. He has since committed the offence again."

The post asked people to share the photo, and it attracted hundreds of comments.

Many outlined various warnings of violence should Singh be identified, and others wrote death threats.

Some comments were racially-charged, labelling him a "terrorist", mocking his turban and calling for his deportation.

But Singh, who arrived in New Zealand seven months ago from India for study, was unaware of the brewing social media storm until his boss called him.

"He told me to go on my Facebook page, because they identified where I work," Singh said.

The photo circulated for eight or nine weeks, before it was taken down, he said.

He had no idea who took the photo, or why it was uploaded.

He has since contacted the Canterbury police and Victim Support.

Police told him they could not help, he said.

READ MORE: Social media should not usurp police response

Victim Support said it had passed on his details to a coordinator to "advise you of what, if anything, Victim Support can do for you around this matter". Singh had not heard anything since.

An apology on the "Missing Persons Christchurch and Canterbury" Facebook page three weeks after the page first posted the photo, asked for forgiveness .

"OK that post is deleted," the new message said.

"Again I apologise. I get I did something wrong. It was a mistake though. As I said I am trying to get justice for my friend."

It was met with further backlash from people calling the administrator "racist" and "irresponsible".

Singh, who lives with his aunt and uncle, said the situation had affected not only him, but also his family.

"It's really affected me, and my family are really scared," he said.

"I can't go outside at night now."

While it had not changed his positive perception of New Zealand, Singh said the online attack had left him with one question: "Who will be responsible?"

"I've felt really, really bad. I haven't done anything," he said.

"I just told them [the police] if something happens to me in the future who will help me?"

Singh said he now wanted to raise awareness in New Zealand on "my culture and people".

CASE BY CASE

Canterbury police district commander Superintendent Gary Knowles said they received a complaint from Singh on January 30, and had spoken to the victim "multiple times throughout this process".

"Canterbury police do not comment on individual complaints of cyber-bullying but we take complaints of this nature very seriously and encourage the public to report any allegations of cyber-bullying," he said.

Cyber-bullying was dealt with a case-by-case basis, he said, and it was an issue "much wider than just police".

Knowles said it was not defined by law and police involvement depended on the case.

"What might be taken as bullying and upsetting by some people may not necessarily be an offence in law," he said.

'SELECTIVE LAW ENFORCEMENT'

Shannon Parker, president of the New Zealand Police Conduct Association, which helps people with complaints against the police, said the police "can and they do" charge people for online harassment.

Police could charge people with misuse of a telephone under the Telecommunications Act, she said.

Charging people under the Harassment Act was harder because police had to get a restraining order or a protection order, before it "becomes illegal".

"The fact is the police should investigate it. They can charge people with the Telecommunications Act and they have previously," Parker said.

She said it was "nothing short of selective law enforcement".

IS IT DEFAMATION?

Media law specialist Jonathan Forsey of Duncan Cotterill said Singh could seek a declaration of defamation, but it would be "clunky" to achieve.

"It's unquestionably defamatory to publish somebody's photo with this allegation of sexual abuse," he said.

However, websites and social media did not have the same "backing" companies and entities had, so it was only their own assets that could be used to pay any damages.

Because the harassment was online it was often difficult to delete all the offending material, Forsey said.

"There are still articles online on the original issue," he said.

He believed Singh should approach the Human Rights Commission or ask police to "have another think about it".

"The Harassment Act is broad enough to cover online activity," Forsey said.