Police in Indonesia aren’t giving up hope of finding missing Australian father Peter Maynard, despite finding a piece of his surfboard.

Police in Indonesia are not giving up on an Australian missing for 12 days, despite finding a piece of his surfboard.

On Monday, Peter Maynard’s family met police searching for the father-of-three, who was last seen on August 27 enjoying a solo holiday on Nusa Lembongan, an island off Bali.

A local man handed in the broken top section of the Queenslander’s Hammo surfboard on Saturday, confirming the family’s fears he went missing in the water.

Detective Nyoman Wirajaya handed over the piece to the family on Monday, but said police might need it back if the disappearance becomes a criminal matter.

Police are not making any assumptions about Mr Maynard’s disappearance and have not given up on findhing him.

“We haven’t decided when the search will be stopped,” Mr Wirajaya said.

He said five Japanese divers survived three days in stormy seas in February after their trip from Nusa Lembongan turned bad.

Another two divers from their party died and their bodies were eventually found.

In 2012, eight divers, from Germany and France, failed to return to their boat in bad weather. They were rescued by chance six hours later by a fisherman who was trying a new route home.

Police say surfing in the area is much safer than diving, and they are baffled by the disappearance of the 45-year-old, who has no known medical conditions and was surfing in relatively calm conditions.

“The coral rock in Lembongan actually makes it not risky for surfing,” Mr Wirajaya said.

“For diving, yes, that’s risky because the current is quite strong.

“In the past five years, there’s never been surfing fatality.”

The search now focuses on the spot called Shipwrecks, where the board piece was found, with all available police and fishermen joining the search.

Mr Maynard’s wife, Kylie, and brother John arrived in Bali on Thursday after learning of his disappearance.