Replica gun found in William Tyrrell search as cops excavate drain

Police searching for William Tyrrell have found a replica pistol and honed in on a muddy culvert as they continue excavating remote bushland for the missing toddler.

Police searching for William Tyrrell have found a replica pistol and honed in on a muddy culvert as they continue excavating remote bushland for the missing toddler.

Meanwhile The Daily Telegraph can reveal the touching good luck symbol carried by one of the dedicated experts focused on finding the missing boy.

Dozens of officers spent day 16 of the extensive bush search raking the sides of Batar Creek Road, less than a kilometre from the home William vanished from in 2014.

Police found a replica pistol on the roadside which has been taken away for forensic testing.

But investigators say it’s not believed to be related to the case at this stage and could have sat in the scrub for years.

Police dig in a muddy culvert on the side of a bush creek where they believe William Tyrrell's remains could be found. Picture: Perry Duffin

The road, where the gun was found, runs over a trickling stream swollen with water after weeks of rain.

The 31st piece of evidence, a tiny fragment, was spotted by one eagle-eyed Riot squad officer and pulled from the culvert where the stream meets the road.

Officers carefully sifted through the earth all afternoon pulling out more foreign items.

The bush appears to have been relatively undisturbed over the years making police hopeful the minuscule pieces of debris could lead them to William’s final resting place.

Professor John Olley wearing a shirt with a wayfinder symbol. Picture: Perry Duffin

Missing boy William Tyrrell.

One expert, hydrologist John Olley, watched as homicide detectives raked through mud scooped from the creek bed on Tuesday.

His black shirt has an intricate white symbol printed on the front - an ancient rune called vegvisir.

Vegvisir represents a wayfinder and is designed to bring lost people home even through bad weather.

More rain is predicted to fall on the town of Kendall on Wednesday but police say they won’t stop working until the bush has given up every thing it holds.