He said authorities wanted to ask him about the Liberal party organization and practices — not about anything he might have done wrong.
"I believe that certain individuals are the object of a police investigation. I won't say more," Couillard told a news conference at the legislature.
"Basically, they were coming to meet the person who was occupying the function of leader of the Liberal party of Quebec.
"They wanted to have comments in general about the ways things are done at the party, other aspects of those practices, but I cannot say anything more than I was authorized to tell you — that I'm not myself the object of any inquiry."
The encounter came after news this week that police raided the Quebec Liberals' Montreal headquarters in July. Both developments were reminders of the ethics scandals that helped knock the party into opposition.
The Liberals have led a number of recent polls, conducted before news of the raid and police encounter with Couillard.
The Liberal leader said none of his current MNAs have been questioned by police.
But that was all he'd say. Couillard said that after his police encounter, which lasted nearly an hour, he and the officers discussed what things he could and could not say without hampering their investigation.
Couillard said he's still "very proud" of leading the Liberal party, which he said has achieved many great things over a 140-year history.
But he said it's going through necessary changes, and anyone who did anything wrong will need to suffer the consequences of their actions.
Couillard pointed out that the police squad that visited him was created by the last Liberal government. However, he conceded that it was a less than pleasant experience to find officers at his doorstep.
"I was walking out the apartment building where I live here in Quebec City... One gentleman and a lady were waiting for me there, they showed me their ID that they were from the (Surete du Quebec) and wanted to have a conversation with me, which we did, at my apartment. I took them back in my apartment and we had this conversation," he said.
"It's not a pleasant human experience, you know. That's something that happens fortunately rarely in one's life. I had seen it only in movies before. It happened in real life."
Quebec's anti-corruption officers have met with different politicians, some of whom were later arrested and some who were simply met for questioning.
One of them, Montreal's ex-interim mayor Michael Applebaum, said after meeting police that he was only helping with an investigation.
But Applebaum was later arrested and now faces corruption-related charges.
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