OTTAWA -- Prime Minister Justin Trudeau remained tight-lipped Monday about the mysterious mission of Liberal MP Nicola Di Iorio.

Di Iorio has not been seen in Ottawa since Parliament resumed sitting Sept. 17.

On Monday, the Prime Minister dodged reporters' questions about the prolonged absence of the MP, who also has an active law practice in Montreal.

Trudeau twice told reporters outside Parliament that they should talk to Di Iorio about it.

Last week, Di Iorio posted a short message on Facebook saying Trudeau assigned him responsibilities that necessitate his absence from the House of Commons.

Things were no clearer during question period when the Opposition questioned the government about Di Iorio's new tasks.

Conservative MP Alain Rayes wanted to know what Di Iorio's "secret mandate" was.

Trudeau was not present, so it was left to Government House leader Bardish Chagger to respond. She said only that all MPs are answerable to their constituents for their work in Ottawa.

First elected in 2015, Di Iorio has sent mixed messages about his political future. In April he announced he was leaving politics without giving a timeline, but in September he said he was still in reflection.