QUEBEC -- The leader of the Quebec Liberals says police seized boxes full of documents in a raid on his party headquarters and he promises his full co-operation with their investigation.

In his first public comments on the July raid by UPAC, the provincial anti-corruption unit, Philippe Couillard said: "I want no compromises. I want the truth."

He said that when police decided not to announce the raid over the summer, he and the party decided to remain silent to avoid interfering with the investigation.

Couillard was asked what police were looking for, and who they were targeting.

"There were so many boxes -- I don't know what was in there," he said Tuesday, adding that some of the seized documents had been returned.

"And I don't want to know... I don't want to intervene in any way in police investigations."

News of the raid appeared in the media yesterday -- on the eve of the reopening of the legislature. The news has overshadowed all other issues at Quebec's national assembly today, including the controversial debate over religious accommodations.

Some Liberal MNAs grumbled on their way into the legislature that they had not been told about the raids before the media report.

That report on Radio-Canada said some Liberal MNAs had been questioned by police but did not specify whether they were current or past politicians.

Couillard says he's also begun asking his current MNAs whether they have been questioned by police and, so far, none say they have.

In recent months, UPAC raids have been the prelude to numerous arrests. The anti-corruption unit, created by the past Liberal government, has arrested more than 100 people.

Couillard says the political environment has already changed in Quebec, with reforms brought in under the Liberals and now the PQ, although he promises more changes in the future.

He says he wants to introduce a code of ethics for his party, specifically, and also for future governments.

He illustrated that point by castigating a party MNA who distributed fundraising letters, in front of a synagogue, in which he listed things the Liberals had done for the Jewish community.

The party has in the past been accused of linking its fundraising to government favours -- such as opening up daycare spaces, which were specifically referred to in the fundraising letter.

Couillard cited one media commentator who called the synagogue fundraiser "awkward." Couillard said it was worse than that.

"It is not awkward... It is inappropriate and unacceptable," he said.

"If a dollar comes into the party that way, I don't want that dollar."

He said every fundraising dollar that comes into the party should come because people support its ideas, not in exchange for past or future favours.

One of those ideas is defending minority rights, Couillard said, in reference to the debate over the Parti Quebecois' proposal to ban religious headwear in the public service.