An attack on a Northland lesbian couple shows New Zealand still has work to do on gay rights, Chief Human Rights Commissioner Rosslyn Noonan says.

Juliet Leigh and Lindsay Heads' business Blooming Bulbs in Mangawhai Heads, a seaside town about 100km north of Auckland, was destroyed by fire on Saturday in an apparent anti-gay attack.

The couple operated the business from a small packing shed next to their home. The fire followed seven abusive anti-gay messages written on their house, cars and shed.

Ms Noonan said while New Zealand generally had a good human rights record, "the incident in Mangawhai shows we still have work to do.

"No one in New Zealand should have to hide or live in fear of being attacked for who they are. It is particularly disturbing when someone is targeted for their sexual orientation."

The attacks outraged the people of Mangawhai, with one woman buying the couple a bouquet of flowers and saying she was "just so ashamed".

The couple have received about 500 emails of sympathy and support.

Ms Noonan welcomed the community's strong message that attacks on people because of their sexual orientation will not be tolerated.

"It is essential a strong message is given that this sort of behaviour is unacceptable and will not be tolerated in any community," she said.

"This message has to start in our homes and schools, workplaces and places of worship, sports clubs and community organisations."