Montreal's transit authority is investigating after a Dorion man says employees refused to serve him in English and mocked him.

Michael Dunning said he was trying to buy a day pass at the Atwater Metro station and was shocked by the reaction of employees at the ticket counter.

"The two people inside ridiculed me, laughed, said all kinds of curse words in French, and said 'We don't serve English people,'" Dunning said.

"Not, 'I don't wanna serve in English,' or 'We don't wanna serve in English.' It was, 'We don't serve English-speaking people.'"

Michael Dunning says when he called to complain, he was informed STM employees are not required to speak English. (CBC) Dunning, a minister with St. Patrick of the Island church, says he tried to call the STM's complaints department to report the incident and was informed the agents are not required to serve customers in English.

However, an STM representative says the incident, if the claims are founded, is surprising.

"I'm flabbergasted hearing that kind of thing because it's impossible . . . Everyone in this service speaks English," Marianne Rouette said.

"They are trained and they are very good people."

Rouette confirmed that employees are not under any obligation to speak any language other than French.

However, she said, they are required to assist customers who don't speak it.

If Dunning's allegations are proven to be accurate, the employees in question could be sanctioned, she said.