The boy was caught in a rip while swimming in large and powerful surf conditions at Lighthouse Beach on December 6.

Despite the best efforts of his 17-year-old brother, who tried to save him, the boy disappeared into the waves and has not been seen since.

On Monday, December 11, NSW Police said the official search effort had been halted.

"The search for an 11-year-old boy who went missing at Lighthouse Beach on Wednesday, December 6 has now ceased," a spokeswoman said.

"Police would like to thank emergency services, volunteers and the community for their assistance with the search."

Community members came together on Sunday in a show of support for the boy's family.

People joined hands at Watonga Rocks and stood silently for one minute to pay their respects to the family. 

"As a parent myself, so many thoughts have been dominating my mind since Wednesday about the poor darling boy, his family and all rescue crews involved," organiser Mandy Davidson said. 

"It is devastating that he is still out there somewhere, and it is so sad that our beautiful little town will now serve as such a horrible reminder for the family.

"I know so many of my fellow community members also have been pained over the past few days with thoughts of the boy and his family.

"If we can allow the family to feel the support and love from our community, I feel it is the least we can do to ease even a tiny bit of pain at this horrible time."

The incident sparked an extensive search, which included Marine Rescue Port Macquarie, lifeguards, emergency services crews and the Westpac Rescue Helicopter. Bystanders on the beach assisted the family until help arrived.

About 20 surf lifesavers and lifeguards from three surf life-saving clubs were also involved in the search, which was scaled back on December 9.

Anyone boating or fishing in this area who comes across anything related to this incident is urged to contact Port Macquarie Police.