A formal request for a royal commission into the death in custody of Palm Island man Mulrinji Doomadgee has been sent to Federal Indigenous Affairs Minister, Senator Amanda Vanstone, and the Governor-General.

Hundreds of residents of the island off north Queensland have signed a petition saying they have little confidence in the Queensland Government's investigations into the death.

Thirty-six-year-old Mulrinji Doomadgee died last November.

Mr Doomadgee's family also say they are unhappy with the Queensland Government's investigations into the death.

Senator Vanstone has refused to comment on the request.

Community spokesman Brad Foster says Senator Vanstone has earlier indicated she would consider a request for a royal commission if it was supported by the people of Palm Island.

"So we as a community have gone out and spoken to the people," he said.

"They've now put pen to paper and they're looking for a response from the Minister Amanda Vanstone."

Queensland Democrats Senator John Cherry says federal intervention may be justified.

"What we need is a commitment from both State and Federal Governments that they're going to address the concerns of the people of Palm Island in an appropriate forum and if that is the cradle inquiry, or if that is a federal inquiry, then so be it," he said.

"If that requires a threat of intervention by the Federal Minister to ensure that happens, then that's what needs to happen."