The Australian Human Rights Commission is investigating a complaint against the New South Wales multiculturalism minister and his department over allegations of racial discrimination against organisations representing south Asian Muslims and caste-oppressed Hindu communities.

According to an email seen by Guardian Australia, the Human Rights Commission last month accepted the complaint, against Steve Kamper and his department, for investigation.

The Human Rights Commission can accept a complaint when it is “reasonably arguable” that the alleged conduct is unlawful discrimination.

The complaint, lodged in December by the Alliance Against Islamophobia and Periyar Ambedkar Thoughts Circle of Australia (Patca), alleges Kamper and Multicultural NSW failed to investigate the groups’ allegations about the Hindu Council of Australia. It was also alleged that both minimised concerns raised by Muslim and caste-oppressed communities.

In a separate complaint, now before the Human Rights Commission, the Alliance Against Islamophobia also alleged the Hindu Council of Australia had engaged in repeated instances of Islamophobia in social media posts.

Surinder Jain, a spokesperson for the Hindu council, said it was not against any community or faith group.

“HCA does not promote or engage in any form of discrimination,” Jain said.

The complaint alleges Kamper and the department continued to endorse the Hindu Council of Australia’s position on the NSW Faith Affairs Council – an advisory body to the government comprising representatives from 12 religions – after being made aware in December that the Human Rights Commission had accepted a complaint against the Hindu group.

Jain said the complaint provided “no reason at all why HCA should not continue in its public role on the NSW Faith Affairs Council”.

“HCA takes that role very seriously and remains (in its respectful opinion) suitable to carry out that role,” he said.

The Alliance Against Islamophobia and Patca also alleged Kamper and the department had failed to meet community leaders to “address widely reported incidents of caste-based discrimination and harassment perpetrated by individuals aligned with Hindu nationalist ideology”.

The complaint also outlines allegations that Multicultural NSW omitted any reference to caste-based discrimination in its state of community relations reports for 2023 and 2024, despite the “existence of substantial community concern” and the “statutory requirement to report on matters affecting community cohesion”.

It also alleged there was an absence of references to Hindu nationalist extremism in these reports.

A spokesperson for Kamper said the minister was aware a complaint had been lodged with the Human Rights Commission.

“The NSW government is committed to ensuring that all communities feel respected and supported, and discrimination of any kind has no place in NSW,” the spokesperson said.

“Multicultural NSW has met with the organisation that made the complaint on several occasions to hear their concerns and have discussed with them at length the matters they raised.”

Guardian Australia has previously reported on concerns within the Indian diaspora about caste discrimination in Australia that remains systemic, according to recent research.

Community leaders have also raised fears about divisions within the Indian-Australian community, with some Hindu nationalists using Facebook and WhatsApp groups to spread divisive rhetoric targeting minority groups including Sikhs and Muslims.

The Human Rights Commission complaint alleges a breach of section nine of the Racial Discrimination Act, which makes conduct involving exclusion, restriction or preference based on race, colour, descent or national or ethnic origin unlawful.

But the commission did not accept the complaint’s allegation of a breach of section 18C of the act, according to the email viewed by Guardian Australia, saying it had not provided information of a reasonably arguable claim of racial hatred.

The commission can facilitate a conciliation process between parties to try to resolve the complaint, but it cannot decide whether unlawful discrimination occurred. If a complaint is not resolved or is discontinued, complainants can lodge action in the federal or circuit court.

Multicultural NSW was approached for comment.