Pauline Hanson says she will quiz her long-time One Nation senator Malcolm Roberts over a series of conspiratorial comments when she returns to Canberra next week, as pressure mounts over a series of podcast appearances that have fuelled fresh scrutiny of the Queensland senator.

The One Nation leader defended Roberts’ record but confirmed she wanted to discuss several issues that had been raised publicly before making any further judgment.

While Roberts remains one of Hanson’s closest political allies, there is growing speculation from within One Nation over whether the 71-year-old will be encouraged to step aside before the next federal election. Party figures, concerned his views are deterring mainstream voters, have privately pointed to concerns about his declining health.

Hanson was asked about Roberts’ support of various conspiracy theories on Thursday after this masthead reported last month he had shared an image of a well-known antisemitic mural, praised US conspiracy theorist Alex Jones as a “beacon of hope around the world” and said Russian leader Vladimir Putin had won his respect for fighting “globalists” in Ukraine.

“There’s a few issues that have been raised, brought to my attention, and until I can sit down and have a talk with [him] next week with regards to it to get to the bottom of the matter. I will do that next week when we’re in Canberra,” Hanson told News24, formerly Sky News.

Hanson sought to defend Roberts against some of the criticism, particularly a report in The Australian in which Roberts claimed it was “highly likely” the US Air Force is spraying “chemtrails” – a debunked conspiracy theory that posits deadly toxins are being released into the atmosphere as part of a secret global depopulation plan.

“Malcolm has never supported the chemtrails,” she said. “You’ve got to understand with Malcolm Roberts, there’s always that scientist that comes out of him, you know, I want to see the data. Everything that he talks about, show me the data. We get lots of people contacting our offices and talking about chemtrails, and he said to me and he says to them, show me the evidence.”

She also suggested media coverage had overstated Roberts’ association with Jones.

“I think that’s my concern,” Hanson said, arguing Roberts did not support everything Jones had said. She said the media had “blown it completely out of proportion” that he supported everything that Jones had said.

Pressed on whether Roberts accepted Jones’ false claims about the Sandy Hook school massacre, Hanson declined to answer directly, saying she wanted to speak to her senator first.

Roberts accused the media of running a co-ordinated “hit job” against him and accused journalists of deliberately misrepresenting his views as One Nation’s rising support in opinion polls placed the party under increasing political scrutiny.

Speaking on The Karl Stefanovic Show this week, he said it had been “deliberate and orchestrated”, potentially involving the Liberal and Labor parties.

He said while “three journalists and three articles” would have been normal accountability, the media ran coverage “day after day after day” to attack him.

He specifically accused News Corp commentators Andrew Bolt and Chris Kenny of misrepresenting him and “twisting and reversing” his position.