Elon Musk’s get-out-the-vote effort for Donald Trump has come under renewed scrutiny after paid canvassers reported not knowing beforehand that they were being hired to support the former president.

Workers recruited by Musk’s America Pac to canvass in the battleground state of Michigan only discovered they were working for the Space X and Tesla entrepreneur to drum up voter turnout for Trump after signing non-disclosure agreements, Wired reported.

“I knew nothing of the job, or much of the job description, other than going door to door and asking the voters who are they voting for,” a canvasser who was flown to Michigan from another state told the website. “Then, after I signed over an NDA, is when I found out we are for Republicans and with Trump.”

The canvassers also said they faced threats to their working conditions if they failed to meet stringent door-knocking targets.

The disclosure comes after the Guardian revealed serious question marks about Musk’s voter turnout effort in Nevada and Arizona amid reports that up to 25% of reported door knocks in the state could be fraudulent.

The Michigan canvassers were hired by Blitz Canvassing, a subcontractor that has so far been paid about $9m by Musk’s Pac to oversee his ground operation aimed at generating turnout in the state.

Recruits reported being told to knock on 1,000 doors a week and to achieve a 17-22% engagement rate – considered a high benchmark for householders opening the door to strangers – to avoid having to pay for their own accommodation and flights home.

“What’s gonna happen is, they’re gonna stop paying for these [motel] rooms, and then you’re gonna end up having to pay for it yourself,” a manager is heard saying in a recording obtained by Wired. “You can’t do that with no money.”

The canvassers also reported being driven to neighbourhoods to carry out door-knocking expeditions in the back of a U-haul van without seat beats, rather than in rental cars, as had been promised. They were dropped off 40 minutes apart to go on door-knocking beats.

None of the workers featured in the report had valid drivers licenses.

A video purportedly shot from inside a van showed mostly Black workers separated from the driver by a cage-like structure. The driver was recorded as telling the workers that he was in pain and having difficulty driving.

“I just had surgery, bro,” the U-Haul driver told the canvassers. “Like half of my foot is cut off.”

One door-knocker said he only learned he was working for Musk’s Pac when he heard supervisors mention the billionaire’s name.

The canvassers were also told to keep the GPS apps on their mobile phones on at all times amid reports that America Pac’s Campaign Sidekick app lacks an effective geo-locator function.

Neither Blitz Canvassing or America Pac have commented.

The latest revelation appears to further highlight the risks of Trump outsourcing the bulk of the task of motivating potential voters to Musk’s Pac in battleground states where he and Kamala Harris are running neck-and-neck in the polls.

The billionaire’s operation has come under fire in Pennsylvania, where a judge has summoned him to appear in court over a lawsuit challenging the legality of his offer of $1m giveaways to registered voters who sign his petition on free speech. Several $1m awards have already been given to people in the state, generally deemed the most important battleground in next week’s election given its 19 electoral college votes, the most of any swing state.

At a time when voters have listed the economy as their primary concern, Musk has also drawn attention by warning just before polling day that ordinary Americans will face “temporary hardships” under $2tn budget cut he envisions implementing in an anticipated role overseeing public spending, which Trump has promised him.