William Tyrrell disappeared eight years ago. Now there's been a new development in the case.

A day after William Tyrrell's 12th birthday, there's been a reported new development in the case of the missing toddler. 

Eight years after the three-year-old disappeared from his foster grandmother's house in Kendall on the NSW Mid-North Coast, police now believe there is enough evidence to potentially charge the boy's foster mother, who cannot be named, 9News reported on Tuesday.

According to the publication, detectives handed a brief to the Director of Public Prosecutions (DPP) this month with evidence against William's foster mother, recommending she be charged with perverting the course of justice and interfering with a corpse.

On Monday, which would have been William’s 12th birthday, NSW Police released a statement saying, "The determination of strike force detectives has never wavered as they continue to meticulously explore and exhaust every line of inquiry."

"As another of William Tyrrell’s birthdays comes and goes – on what should be a happy occasion – the NSW Police Force continues to actively and vigorously search for answers into his disappearance."

There is no suggestion of guilt and it is now up to the DPP to assess the evidence to determine if the findings will be tested in court.

The now-58-year-old woman has always denied any involvement in her foster son’s disappearance.

- More to come. 

Read more: 

It's been 8 years since William Tyrrell disappeared. Here's everything we know about the case.

Feature Image: AAP.