Twenty-two US senators signed a letter to President Donald Trump on Wednesday, triggering a US investigation and determination of whether human rights sanctions should be imposed over the disappearance of a Saudi journalist last seen as he entered the Saudi consulate in Turkey.

In the letter, the senators said they had triggered a provision of the Global Magnitsky Human Rights Accountability Act requiring the president to determine whether a foreign person is responsible for a gross human rights violation.

“Our expectation is that in making your determination you will consider any relevant information, including with respect to the highest ranking officials in the Government of Saudi Arabia,” they said.