First Nation’s groups are warning proposed changes to the Aboriginal Heritage Act in South Australia could reduce the powers of traditional owners.

While amendments to the act were passed through the Legislative Council last week, Indigenous groups are saying they have not been consulted.

South Australian Native Title Services CEO Keith Thomas says amended language in the act will give traditional owners less say and will make it harder to prosecute companies if they disturb a sacred site without approval.

Aboriginal Affairs Minister Kyam Maher has defended the proposed amendments, saying they would not change the level of protection, and rejected claims that Indigenous groups had not been consulted.

The amendments are due to be introduced into the Lower House during the next sitting week.