Yoon Seok-youl, a leading opposition presidential contender, drew fire Friday after a photo of his dog being fed an apple sparked speculation that he likened the people to a dog following a reluctant apology for making insensitive remarks about a former dictator.

In Korean, "apology" and "apple" are homonyms and the fact that Yoon's dog Tory was given the fruit only hours after the candidate issued a public apology led to criticism that Yoon was insincere in his apology and dismissed the people as dogs.

The photo was posted on an Instagram account under Tory's name on Thursday night and later deleted.

"Such mockery of the people should really not be done," Rep. Song Young-gil, the chairman of the ruling Democratic Party, said during a party meeting. "If he wants to apologize, he should do it properly."

Yoon's rivals within his own People Power Party (PPP) took the criticism a step further.

"If this isn't saying 'apologies are for dogs,' what is this?" a spokesperson for PPP presidential contender Hong Joon-pyo said in a statement.

The spokesperson added, "(Yoon) is treating people who don't understand his mistakes and criticize them as dogs. How is such a candidate fit to be a presidential candidate of the People Power Party?"

The campaigns of former PPP Rep. Yoo Seong-min and former Jeju Gov. Won Hee-ryong, the two other contenders running in the PPP presidential primary, released similar statements, saying responsibility does not stop at whoever handles Yoon's social media accounts.

The apology in question followed criticism that Yoon praised former authoritarian President Chun Doo-hwan by claiming many people believe he conducted state affairs well, except for his bloody suppression of a 1980 pro-democracy uprising in the southwestern city of Gwangju and his seizing power through a coup.

Yoon initially expressed "regret" over the remarks but followed up with an apology.

PPP Chairman Lee Jun-seok left a cryptic message on Facebook on Friday morning.

"I woke up this morning to something that defies common sense ... I'm at a loss," he wrote. (Yonhap)