Trinamool BNP Chairperson Shamsher Mobin Chowdhury and his wife have been barred from travel abroad.
They were sent back from Dhaka airport on Wednesday.
The immigration police allegedly did not allow them to board their flight without clearance from "top-level" authorities.
He alleged that while they were waiting in the VIP room, the immigration police took their passports, claiming they needed to make copies.
They kept thier passports for a long time and delayed them deliberately, he claimed.
"When I asked, they said I needed clearance from an intelligence agency."
Mobin said he showed a 2010 court ruling saying that he should not face any obstacles when travelling abroad, but that was ignored. He was advised to contact higher authorities.


