The grey hooded jumper that has sparked the intensive police search of the Blue Lagoon in Milton Keynes was spotted by a walker in FEBRUARY, it has been revealed.
But the witness who saw it did not realise the significance because she was unaware of the Leah Crouches case details.
The witness, believed to live locally, was prompted to contact police during the recent flurry of national publicity, which included a feature on Crimewatch Roadshow.
She saw a photo of the distinctive hoodie, which has the words Stewartby Taekwondo on the reverse. This is the name of the martial arts club where Lea's dad is an instructor and where Leah trained to championship level.
The word Stewartby is understood to have stuck in her mind.
She told police the hoodie was on the ground, right next to the lake, but not in the water.
After receiving her information, police decided to launch a full scale search of the Blue Lagoon lake and surroundings using tracker dogs and a helicopter.
It is understood they have not yet found the hoodie or any other evidence pointing to Leah.
Now 20, Leah disappeared on February 15 while walking from her home in Emerson Valley to her workplace in Knowhill.
If you have any information about her at all please call police on 101 quoting reference 43190049929 or call Crime stoppers anonymously on 0800 555 111.
Meanwhile, the Citizen is re-publishing photographs of all the clothing and personal items worn or carried by Leah on the day she vanished.
Seven and a half months on, none of them have been found.
The search of the Blue Lagoon started on Wednesday last week. It is expected to last for 10 days.