Celtic midfielder Ki Sung-Yeung was allegedly the target of repeated taunts during Saturday's match at McDiarmid Park.
A small minority of fans were heard to bark at the South Korean star.
Some mindless fans also chanted "Who ate all the dogs?" at the 21-year-old during the clash.
At one stage the player, known as Ki, went to take a corner to be met by a group of fans "woofing" at him.
The song "Who ate all the dogs?" was also heard during the televised lunchtime encounter.
It is understood that the tasteless taunts refer to the reported use of dogs in Korean cuisine.
On various fans forums there was a furious backlash from fellow St Johnstone followers, many of whom described themselves as disgusted.
"Racism, sectarianism and bigotry should have no place in the modern game," one said.
"Would we laugh it off if monkey noises were made at Dubes (St Johnstone's black defender Michael Duberry) or would we be complaining about that?
"I don't think anyone would laugh it off."
He added, "In my opinion the same applies to going 'woof woof' to Korean players."
Fan "cannot express my disgust"
The writer described the incident as embarrassing.
He said, "Had to explain to my seven-year-old what the woofing was about...not fun."
Another fan said the yobs risked tarnishing the good reputation enjoyed by St Johnstone followers.
"The Saints fans going woof woof at the South Korean... are an embarrassment to the club," he said.
Another web user added, "Saints fans have a go at sectarianism of the Old Firm but condoning the woofing at Ki is hardly any better to be honest.
"At least condemn both and don't be a hypocrite."
One regular contributor said, "I hoped that I had perhaps imagined it on Saturday.
"It appears I didn't and cannot express my disgust enough at those who participated."
St Johnstone officials last night moved swiftly to act upon the allegations of racism.
"It has been brought to the club's attention that an extremely small minority of our support may have been responsible for making racist noises toward certain Celtic players during Saturday's game," a spokesman said.
"St Johnstone FC will conduct a thorough investigation into these allegations.
"We will consult both the police and our stewarding suppliers, G4S."
He added, "Additionally, we are appealing to fair-minded Saints fans, who make up the overwhelming majority of our support, to let us know if they are able to identify the individuals who may have been responsible."
The Courier
