OTTAWA - Two more Conservative staffers have been implicated in trying to block access to government records but their boss is refusing to say whether he has passed on their files to the federal information commissioner.

The involvement of Natural Resources Minister Christian Paradis' staff in access-to-information files was raised by all three opposition parties during question period Thursday, with some MPs calling for the minister's resignation.

A former aide to Paradis, Sebastien Togneri, resigned in October when it emerged he intervened at least four times in the release of government records while Paradis was Public Works minister.

The Canadian Press reported Wednesday that two other members of the minister's political staff, Jillian Andrews and Marc Toupin, also tried to stop the release of documents on at least two separate occasions in 2009.

Such meddling by political staff is expressly forbidden, and the Prime Minister's Office has reminded staff to adhere to the legislation.

Paradis' office also failed to answer questions about whether Andrews and Toupin reported to Togneri on access-to-information issues, whether they currently handled access-to-information files, and whether they had ever been reprimanded for their actions relating to the release of records.

"The minister pretended he had no idea what was going on. That is possible if only one staffer were involved, but there were three, if not more. This has the smell of a cover-up," said Liberal MP Wayne Easter.

"How bad does it have to get for the prime minister to act? Just what is it going to take for the prime minister to fire that minister?"

Paradis did not rise to answer questions about the issue in the Commons, but government House leader John Baird said the information commissioner is studying the file and that they are awaiting her report. He also emphasized that Paradis accepted Togneri's resignation.

"The Access to Information Act is very clear. Every bureaucrat, and every political aide is obligated to follow the law. That's the real policy of the government," Baird said.

But neither Baird, nor Paradis' office, could confirm whether information commissioner Suzanne Legault had in her possession the same documents that The Canadian Press obtained through Access to Information legislation this week that dealt with Andrews and Toupin specifically.

Legault's office received a package of 1,200 documents in October from Public Works, which were also tabled with a Commons committee. Those documents did not include the records received by The Canadian Press.

A spokeswoman for Legault said she could not comment on an ongoing investigation for privacy reasons.

Legault currently has two investigations underway sparked by documents that involved Togneri. The first involved an access-to-information package of documents that was being sent to The Canadian Press, but which Togneri demanded bureaucrats retrieve from the mailroom and redact.

The second investigation began following the release of documents to the committee in the fall, and a story written by The Canadian Press detailing other incidents in which Togneri intervened.

The files the staffers tried to block, and which have been revealed in publicly disclosed documents, involved politically sensitive topics including asbestos and U.S. President Barack Obama's visit to Canada.

It is not clear from internal departmental emails whether the access files being discussed by the political staffers and bureaucrats were ever divulged.