THE sudden deaths of six native birds in Tweed has alarmed authorities who fear they may have been poisoned.

Four crows, a currawong and a brush turkey were found dead in the east Cudgen area.

NSW Office of Environment and Heritage senior public affairs officer, Lawrence Orel, said the deaths of the currawong and the brush turkey were reported on Monday afternoon.

“Yesterday we've had reported two protected native species that have been found dead, possibly poisoned.

"These two native species follow the death of four crows and one has recovered,” Mr Orel said.

In NSW it is an offence to harm a protected species without a permit or authorisation, but crows are not protected in the regions.

“Crows in regional areas can be ‘controlled', but certainly it does need to be done with the approved methods,” he said.

“If people are using poisons they need to use poisons in accordance with the purpose for which they are designed.

“That's marked very clearly on the labels for them.”

Currumbin Wildlife Sanctuary senior vet Michael Pyne said he was surprised it was legal for people to bait crows in NSW.

“That blows me away ... I would have thought you at least need a permit to do it,” he said.

Director of wildlife with the Queensland Department of Environment and Resource Management, Nick Rigby, said the rules in Queensland were clear.

“Where wildlife is causing damage or loss which cannot be prevented, the Department of Environment and Resource Management will consider issuing a damage mitigation permit to manage the issue,” Mr Rigby said.

“Crows are protected under the Queensland Nature Conservation Act.

"People illegally killing native birds such as crows face penalties of up to $10,000 per bird.”

Mr Orel said he could not say for certain if the birds were being poisoned.

“We really do need information from people from the east Cudgen area,” he said.

“We are appealing to anybody who has any information about if protected native species are being poisoned.”

Anybody with information is being urged to contact the Office of Environment and Heritage on 131555.