Still missing: William Tyrrell vanished from his foster grandmother's home three-and-a-half years ago
September 12 - Dressed in a Spiderman outfit, three-year-old William Tyrrell goes missing from the garden while visiting members of his foster family on the NSW north coast.
September 21 - Police stop searching for the missing boy after scouring surrounding bushland and neighbouring houses.
January 20 - Police search the home and business of a washing machine repairman, who had been due to carry out repairs at the house at the time the three-year-old went missing.
Detectives take items for testing including a mattress, computer and vehicles. They drain his septic tank.
January 23 - The washing machine repairman publicly denies any involvement in William's disappearance and says he and his wife are on the verge of a breakdown due to the public attention.
February 19 - Homicide detectives take over the case and say it's likely William was abducted.
March 2 - Police fruitlessly search an area of bushland near Bonny Hills for three days after a tip-off.
April 17 - William's foster parents speak publicly for the first time in an emotional video released through police which does not identify them.
April 17 - Police say the boy may have been a victim of a pedophile ring.
September 6 - The Nine Network's 60 Minutes airs a special report into the case, revealing two suspicious cars were parked on the street the morning William went missing.
September 12 - 'Where's William' week is launched one year after he disappeared.
September 12 - A $1million reward is offered