Two men were attacked while swimming at a beach in the popular coastal resort of Puerto Vallarta.
The Australian man said he had no choice but to kill the animals, and criticised a rule change that meant pet crocodiles were being "put on death row.”
Villagers feared that the tyre would eventually choke the growing reptile.
Crocodiles play an important role in Singapore’s ecosystem and hold an interesting key to its past.
He would be the third man to have been attacked by a crocodile in Australia in as many weeks.
Local wildlife and forestry officials condemned the shooting.
The crocodile's partner, Bonnie, is in mourning.
Fifty-nine baby crocs went missing from a Darwin reptile park last month. "I’d like to know who’s doing it," says the park owner. "What are you going to do with 59 crocs?"
The tyre has been stuck around the reptile's neck for years, but no one’s up to the task of saving it.
Despite warnings of crocodile attacks being on the rise, the villagers felt that since the croc wandered into a temple, it was ‘auspicious’.
Police are reportedly on the lookout for a man who goes by the name of Mr Ochiai: an exotic animal collector whose pet crocodile just ate one of his employees.
The Government wants to confiscate Vicki Lowing's pet reptiles.