Authorities are tight-lipped about the circumstance surrounding the death of an experienced Qantas Airways Boeing 747 pilot, who crashed a small plane off the Australian coast this week.

Officials say Paul Whyte was the only person aboard a rented Cessna 172 when it vanished from radar late Monday over the Pacific Ocean northeast of Byron Bay.

The Australian Transport Safety Bureau, which investigates fatal air crashes, said on Thursday it was not investigating Whyte's death. The bureau would not explain why.

New South Wales Police say they are preparing a report for a state coroner who will make an official finding of the cause of Whyte's death. Police say there are no suspicious circumstances surrounding the tragedy, but will provide no further details.

Whyte's body has not yet been recovered.