Oregon’s senior U.S. senator wants the Trump administration to explain how a Saudi citizen jumped bail and apparently fled to his home country with his government’s help just before his manslaughter trial in Portland.

In a letter Friday, Sen. Ron Wyden asked two of Trump’s top Cabinet members what the administration is doing to get Abdulrahman Sameer Noorah back and hold him accountable for allegedly running down teenager Fallon Smart. He called for a thorough investigation of Noorah’s disappearance.

Federal law enforcement officials told The Oregonian/OregonLive this week they believe the Saudis helped orchestrate Noorah’s remarkable 2017 escape and that the young man arrived back in Saudi Arabia 18 months ago.

The revelations have since garnered international attention.

“These are shocking claims in any event, but with the barbaric murder of U.S. resident Jamal Khashoggi, they suggest a brazen pattern of disregard for the law and abuse of diplomatic privileges,” Wyden wrote to Secretary of State Mike Pompeo and the acting attorney general, Matthew Whitaker.

“If they are accurate, they would require significant restrictions on Saudi Arabia’s diplomatic privileges and call into question the future of America’s bilateral relationship with the Saudis.”

Khashoggi, a journalist, was killed and dismembered inside the Saudi consulate in Istanbul this fall, according to Turkish officials. The CIA believes Saudi Crown Prince Mohammed bin Salman ordered the killing.

Wyden, a Democrat, sits on the Senate’s Select Committee on Intelligence.

Portland police say Noorah, a Saudi national, was speeding on Southeast Hawthorne Boulevard when his car fatally struck Smart, 15, while she crossed the street in August 2016.

The then 20-year-old had 17 parking violations as well as a suspended license for driving without insurance at the time of his arrest, according to court documents.

Records show Noorah had been a student in Portland since 2014 and received an $1,850-a-month stipend from the Saudi government for living expenses.

After his arrest, the Saudi consulate retained private defense attorneys to work on his case and cut a $100,000 check to provide him bail, according to court records and prosecutors.

Two weeks before his June 2017 trial, authorities say, Noorah cut an electronic tracking monitor he was required to wear as a condition of his release and disappeared.

Officials with the U.S. Department of Homeland Security and U.S. Marshals Service now believe he left his Southeast Portland neighborhood in a black SUV and later used an illicit passport and private plane — likely provided by the Saudi government — to flee the country.

This past July, more than 13 months after he first disappeared, the Saudis contacted Homeland Security to inform the agency Noorah was back home.

The U.S. and Saudi Arabia have no extradition treaty, which means an arrest of Noorah inside the kingdom is unlikely. Nor have federal officers confirmed the young man’s precise whereabouts within the Middle East nation.

“Since the U.S. does not have an extradition treaty with Saudi Arabia, what steps is the Trump administration taking to ensure Mr. Noorah is accountable for the death of Ms. Smart?” asked Wyden in his letter to Pompeo and Whitaker.

The senator said he also wants to know if the Trump administration has evidence of other assistance the Saudi government provided to Noorah.

He asked the State and Justice departments for answers no later than Jan. 31. The departments did not respond to requests for comment.

Read Wyden’s full letter here.

-- Shane Dixon Kavanaugh; 503-294-7632