A group of Senators are demanding President Donald Trump and his sons disclose information about the family’s business ties to Saudi Arabia following the disappearance of U.S.-based Saudi journalist Jamal Khashoggi.

The 11 Senators, all Democrats, asked Trump to reveal any business ties between the Trump Organization and Saudi officials. In a letter published by Axios on Wednesday, the Senators requested that Trump “commit to suspending any ongoing business relationships” with the Saudis while the investigation into Khashoggi’s disappearance is ongoing.

“Your recent statements, and public reports of increased spending by the Saudi government at Trump properties, raise significant concerns about financial conflicts of interest,” the Senators wrote.

Read more: Donald Trump: List of His Biggest Conflicts of Interest

Khashoggi, a Saudi national and Washington Post columnist, was last seen entering the Saudi consulate in Istanbul, Turkey on Oct. 2. Based on alleged video and audio evidence, Turkish officials have drawn a grisly picture of Khashoggi’s execution by a specially dispatched Saudi security team. On Wednesday, the New York Times, citing a Turkish official, reported that audio recordings from inside the Saudi consulate reveal Khashoggi was killed and dismembered within minutes of arriving.

But Trump has declined to forcefully challenge Saudi Arabia over the dissident’s disappearance. Instead, he has defended the value of American arms sales to Saudi Arabia and emphasized that Khashoggi was not an American citizen. On Wednesday, Trump said the U.S. has asked for the audio and video recordings in the Khashoggi case, but cast doubt on whether such evidence actually exists.

Read more: We Must Use the Global Magnitsky Act to Punish the Killers of Jamal Khashoggi

The Senators’ letter cited big-ticket past transactions between Trump and members of the Saudi royal family, including the $325 million sale of New York’s Plaza Hotel in 1995 “in a deal to pay off Trump Organization debts.”

The letter also cited an Associated Press report that showed in 2001, Trump sold the entire 45th floor of the Trump World Tower to Saudi Arabia for $12 million. As Trump’s presidential campaign was getting underway in 2016, he also registered eight companies in Saudi Arabia that appeared connected to hotel deals in the country. On Monday, Trump tweeted that he has “no financial interests in Saudi Arabia.”

Last week, a bipartisan group of 22 Senators triggered an investigation of Saudi Arabia under the Global Magnitsky Act. The results of the probe could see Saudi officials face sanctions including asset freezes and visa bans.

“It is imperative that this sanctions determination, and U.S. policy towards Saudi Arabia generally, are not influenced by any conflicts of interest that may exist because of your or your family’s deep financial ties to Saudi Arabia,” the Senate Democrats wrote.

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Write to Eli Meixler at eli.meixler@time.com.