Couple denies involvement in William Tyrell disappearance, in first public statement

The husband and wife caught up in the investigation into William Tyrell's disappearance say they're at breaking point, as they publicly deny any involvement.

It is the first time we've heard from Bill and Margaret Spedding, who've spoken candidly to 9NEWS about the immense pressure they're under.

The Speddings have been thrust into the spotlight after homicide detectives raided their home and business, as part of the investigation into missing three-year-old William.

In just two days, their lives have been turned upside down.

"We're both close to a nervous breakdown," Mr Spedding said.

"We're co-operating with the police fully," he said.

Struggling to understand the events unfolding around them, the Speddings make a point to thank family and friends for their support.

"It has been difficult. We want to thank our family and friends for the overwhelming support we have received," Mr Spedding said.

Police arrived at their home in Bonny Hills, near Port Macquarie, at 7.30am on Tuesday. 

They spent 48 hours excavating the backyard and emptying a septic tank.

At the same time, their pawnbrokers shop in Laurieton was searched.

Detectives have sent away three cars, mobile phones, a mattress and computer equipment for forensic testing.

Police say that process could take weeks, leaving the Speddings in a nightmarish limbo.

"(It's) the children I'm worried about, because it affects them too," Mrs Spedding said.

They came to the attention of police following an anonymous call to Crime Stoppers. 

A tradesman, Mr Spedding had visited William's grandmother's house here in Kendall on Monday September 8 to fix her washing machine.

That Friday, the three-year-old vanished.

The husband and wife say they have nothing to do with William's disappearance and are just doing their best not to come apart.

"We'll get through this. We'll stick together," Mrs Spedding said.