The lake that police are searching as part of the Leah Croucher investigation is used twice a week by a sub-aqua diving club whose members know every nook and cranny.
Milton Keynes Sub-Aqua Club members dive every Wednesday during the summer and every Sunday all year round at the Blue Lagoon nature reserve in Bletchley.
The have planted boats, two cars, a minibus and concrete pipes to swim through. And they even have part of a Cessna plane at the bottom of the lake for up to 20 divers at a time to explore. They have also built three special underwater diving platforms.
Some MKSAC members have been diving at the Blue Lagoon for more than 30 years, and are said to know the former clay pit “like the back of their hand”.
The club has confirmed that members have never found anything suspicious or linked to Leah in the lake.
They also confirmed it was NOT one of its divers who spotted the vital clue that has led to the police search – the distinctive grey hoodie she was wearing on the day she disappeared.
This has opened up questions as to how the item of clothing has sat undetected for the past seven months in this popular beauty spot, which is a haven for hundreds of dog walkers.
This morning police recruited a specialist police diving team to scour the lake, while officers are searching the surrounding woodland.
They say the move comes after a member of the public “has described seeing” a hoodie that may be linked to Leah.
On the morning Leah vanished she was wearing to work a grey hooded top with the logo of taekwondo club on the front and the words Stewartby Taekwondo written across the back. This is the club where Leah's father John is an instructor and the hoodies are relatively rare.
Leah was last seen on February 15 in Buzzacott Lane on Furzton, which is four miles away from the Blue Lagoon.
The nature reserve was built on the site of the former London Brick Company brick works.
Owned and maintained by MK Council, it consists of a large, steep-sided pit filled with water around 60 ft deep. Around this is grass and dense woodland.
The water in the pit is so clean and deep that it turns a deep shade of blue in the right light, giving the nature reserve its name.
The police search, which includes dogs and a helicopter, is expected to last for several days.