NSW Police have laid fresh charges against William Tyrrell's foster mother for stalking and intimidation.
Detectives formally charged the 56-year-old, who cannot be identified for legal reasons, last Friday but a NSW Police spokeswoman would not comment on the nature of the alleged incident.
"As there are non-publication orders in place, we are not in a position to comment," she said.
The toddler's foster mother is already before the courts for a separate count of common assault against a child, for which she has pleaded not guilty.
William's foster father has also been charged over the same assault, which allegedly occurred at a home in Sydney's north.
The child is not William Tyrrell and the specific allegations against them are suppressed.
The couple has denied any wrongdoing.
William Tyrrell vanished from his foster grandmother's home at Kendall on the NSW Mid North Coast in September 2014.
A new search of bush, about a kilometre from the Benaroon Drive property where the late foster grandmother used to live, was conducted at the end of 2021.
At the time, NSW Police Commissioner Karen Webb said she was confident officers would make a breakthrough.
"There's no stone being unturned," she said.
The operation failed to find any trace of the boy who disappeared wearing a Spider-Man suit.
His foster mother remains on bail and is expected to face Hornsby Local Court on April 29.
