Several Liberal MPs say they are unable to explain the prolonged absence of their colleague Nicola Di Iorio, who hasn't been seen on Parliament Hill since the House resumed sitting Sept. 17.

The Montreal-area MP said in late September that he was mulling over his political future but has yet to confirm a departure.

Questioned Wednesday in Ottawa, several of Di Iorio's fellow Liberal MPs professed to be in the dark about his intentions.

"I haven't seen him … and I have no idea what's going on with Mr. Di Iorio," Montreal-area MP Michel Picard said.

A similar message came from Diane Lebouthillier, who said, "I haven't seen him either, so I can't give you any more information."

Montreal MP Emmanuel Dubourg said Di Iorio's absence had been noted, but "I don't know his exact position, what he plans to do."

Ontario MP John McKay expressed confusion. "I thought he quit," he said.

While Di Iorio has been absent from Parliament, he hasn't gone entirely missing from the public eye.

'Between Mr. Di Iorio and his constituents'

Last Friday, he appeared at a cannabis trade show in Montreal, where he made a presentation in his capacity as a labour and employment lawyer.

MPs questioned on Parliament Hill Wednesday appeared reluctant to discuss the subject of a colleague working a second job.

"That's between Mr. Di Iorio and his constituents," said David McGuinty as he walked past waiting journalists.

McKay acknowledged that "from an image standpoint, it certainly doesn't look good."

There are no rules preventing an MP from moonlighting.

Similarly, MPs are not technically required to show up in Ottawa to keep their seats, although many say it's part of the job.

"Personally, as a member of Parliament, it's important to be here in the House," said Democratic Institutions Minister Karina Gould.

"As an MP, you have responsibilities [to] your community to make sure to be here. That's why the House of Commons has rules to ensure MPs come."

In 2017, the base annual salary for an MP was increased to $172,700. According to parliamentary rules, an MP who is absent from the House can be docked $120 of salary per day for each absence over 21 days.

Exceptions apply in cases of sickness, military service or official engagements. It's unclear whether Di Iorio has been penalized.

Di Iorio has sent mixed messages about his political future.

Watch Nicola Di Iorio outline the reasons he has decided to step down as an MP:

Nicola Di Iorio, Liberal MP for the riding of Saint-Léonard–Saint-Michel, outlines the reasons he has decided to step down as a Member of Parliament. 1:28

First elected in 2015 to represent the Montreal riding of Saint-Leonard-Saint-Michel, he announced last April he was leaving politics for family reasons.

He later told a weekly newspaper he would stay on until the end of his mandate in 2019, before writing on his Facebook page in late September that he was giving himself another month to reflect on his future.

In a brief phone interview last week, he maintained that he has never stopped serving his constituents.

Liberal whip Mark Holland said last week that Di Iorio would explain himself in a statement in "a few days' time."

On Wednesday, Holland's office said they had nothing new to add.