A mysterious flying object has landed in Australia leaving a huge crater where it sank into the mud.

Worldwide attention is focusing on the town of Guyra, 250 miles north of Sydney, as debate rages about what slammed into the ground.

Rumours range from the incredible such as a space craft to more realistic theories such as frozen sewage from a passenger plane.

The 50ft by 20ft crater crashed into earth near a dam and police have now erected a one mile no-go area.

"Significant depression"

Experts have tested the site for radioactivity but have found nothing although water supplies have been cut to Guyra as a precaution.

A police spokesman said: "At this stage we don't really know what the object is. 

"It has made a significant depression in the floor of the dam."

The mysterious object, which landed sometime between Monday and Wednesday, appeared to hit the dam at about 45 degrees and skidded before sinking. 

The spokesman added: "They have had a close look at the surface of the crater and it seems that the reeds have actually been flattened not broken."

Baffled

Divers have headed to Guyra to inspect the dam, and more tests are being carried out on the crater and the surrounds.

A local government worker stumbled on the crater inadvertently on Wednesday when he arrived at the dam for routine maintenance. 

Baffled residents said there had been no sightings of falling stars, loud noises or earth tremors in recent days.