Former Umno leader Khairuddin Abu Hassan was supposed to meet the United State's Federal Bureau of Investigation (FBI) over 1MDB on Monday before he was detained.
His lawyer Matthias Chang told the New York Times that the meeting had been arranged by the US Embassy in Kuala Lumpur.
The report said Khairuddin had planned to urge America's law enforcement to probe 1MDB for money laundering.
However the plan was derailed after the Immigration Department barred the former Batu Kawan Umno deputy chief and Chang from leaving the country yesterday.
Khairuddin was later arrested under Section 124C of the Penal Code for attempting to commit acts detrimental to parliamentary democracy.
Prior to his arrest, he had agreed to go to Bukit Aman on Monday for questioning over documents he had submitted to the Swiss authorities regarding the 1MDB scandal.
He said he did so to fight for the people against Prime Minister Najib Abdul Razak.
Najib has repeatedly denied misusing 1MDB funds for his own personal gain and vowed to solve 1MDB's debt situation soon.
In the face of growing criticism over 1MDB and his leadership from both sides of the political divide, the prime minister has defended himself claiming there is a conspiracy to topple him and his government.