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When passengers complained of a strange odor aboard Qantas Flight 825 en route from Darwin to Brisbane on Sunday, officials made the decision to land the plane as soon as possible.

Rather than a security threat, officials found a dirty diaper that had been left in one of the plane's toilets, at least according to the  Daily Mail. 

But something doesn't smell quite right. Qantas now tells ABCNews.com that despite multiple checks, engineers were unable to pinpoint the exact cause of the odor. Though the Daily Mail went as far as to quote a statement supposedly given by the airline regarding the diaper incident, an airline spokeswoman said the reporting is "not correct."

Qantas did confirm, however, that the flight made an unscheduled stop in Mount Isa, Australia, and passengers needed to be removed both by aircraft hi-lift and stairs.   Mount Isa is  a smaller airport that isn't able to handle an aircraft as large as the Qantas aircraft.  A B737 took the affected passengers to Brisbane later that night.

Soiled babies aren't the only ones holding up travelers recently. Animals are just as guilty.

A United flight from Chicago to Portland was forced to return to the airport Thursday because of a bird strike.

And just last week, a cat that got loose in the cockpit delayed a flight as the crew struggled to find the feline. "Ripples" the cat was found safe and sound and returned to his owner, but not before passengers were forced to deplane and delayed for four hours.

The users of popular frequent-flier website flyertalk.com have chronicled a few of their own weird flight delays over the years. One flier claims to have been delayed two hours because of a frozen toilet, while another was held up because the pilot was arrested. Another poster was delayed when a carry on fell out of the overhead bin and knocked a flight attendant out cold.