Nakai, an 11-year-old captive killer whale, was left with a dinner-plate sized chunk of flesh missing from just under his mouth after a performance with two other orcas in SeaWorld, California.
SeaWorld has insisted that the horrific wound was caused by Nakai coming "into contact with a portion of the pool". But speculation over how the whale was injured has been stoked online by a number of unexplained factors.
On the night of the incident, Nakai and the two other killer whales, Keet and Ike, reportedly broke from a routine and started "fighting". SeaWorld staff could not explain the fight or identify which of the orcas had been the instigator.
It was only later when staff went to feed Nakai that they noticed the wound on his chin and retrieved the missing chunk from the bottom of the pool.
A close up picture of the nasty gash shows what appear to be teeth marks around the edge of the wound, spaced apart in a similar fashion to Nakai's teeth, fuelling rumours that it is in fact a bite.
The statement released by SeaWorld has also sparked debate. Beyond giving the explanation that Nakai came into contact with a portion of the pool, it says little else other than he is on antibiotics and appears to be healing well.
David Kirby, author of Death at SeaWorld: Shamu and the Dark Side of Killer Whales in Captivity, wrote on environmental website Take Part: "In the wild, orcas rarely, if ever seriously hurt themselves on “portions” of the ocean like rocks and reefs (their astounding echolocation abilities see to that), although boat propellers can cause awful cuts and gaping gashes.
"Likewise, wild orcas rarely, if ever, take giant chunks of flesh from each other.
"Not only would it be taboo in killer whale society, altercations don’t typically lead to life-threatening injuries.
"For one, a whale under attack can easily get away from its aggressor in the open sea, but not so at enclosed SeaWorld and other entertainment parks.
"In either case, SeaWorld only has captivity to blame."
Below is Nakai in happier times, showing off with a little belly jig...