The White House coronavirus task force is buying mask-cleaning machines promoted by President Donald Trump at a huge markup, possibly 10 times the original cost, according to documents obtained by NBC News. But the machines appear to damage N95 masks, and health care workers are questioning their safety.

The contracts for the machines are the latest example of how the task force, working without external oversight, has pumped billions of dollars into hard-to-trace contracts for COVID-19 supplies as part of Trump’s search for silver-bullet solutions and deals to announce. But the results often don’t pan out as advertised.