Some legal experts -- including Fox News' Judge Andrew Napolitano -- have said acting Attorney General Matthew Whitaker's appointment is unlawful, but former independent counsel Ken Starr disagrees.

Whitaker’s appointment has been under fire ever since it was announced last week, coinciding with the resignation of then-Attorney General Jeff Sessions, with Democrats questioning his qualifications and views on Special Counsel Robert Mueller’s investigation.

The state of Maryland is reportedly set to launch an unprecedented legal challenge to Whitaker's appointment.

Napolitano and others have argued that Whitaker is not legally qualified to be acting attorney general, because his role at the Justice Department at the time of his appointment did not require a presidential appointment or Senate approval.

On "America's Newsroom" Tuesday, Starr said he believes the appointment is lawful, arguing the Vacancies Act allows the president to temporarily fill a position that requires Senate confirmation with any official who’s been in the department for more than 90 days.

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"Legitimate questions have been raised, but I think it's a lawful appointment," Starr said.

He added that the law makes it clear that an acting attorney general appointed in such a way cannot serve indefinitely, and the idea is to fill the role while a permanent candidate is selected by the president and vetted by the Senate.

He said that ordinarily the deputy attorney general -- in this case, Rod Rosenstein -- would take over as acting attorney general, but Trump apparently "saw fit to go in a different direction."

As for calls for Whitaker to recuse himself from the Russia investigation due to past comments about the Mueller probe, Starr said everyone should let the process play out.

"We want the Justice Department to do its job, the attorney general to do his job, in an upright and lawful way, and that includes appearance issues," Starr said. "See what the Justice Department ethics officers have to say and then see what the attorney general determines."

See more from Starr above.

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