Tajul Islam Faruk alleged to police that Hasina had extorted about $436,000 from him.

"The case alleged that Hasina compelled the management of a private power plant to pay the amount in phases from 1998 to 2001, otherwise threatening to stop the operation of the company," Mohammad Jashim, a police officer said, reading out the complaint.

Tajul had a stake in the power plant, although further details of his involvement were not immediately available.

"This is baseless and a blatant lie. We will fight it as per legal provisions," the Awami League rebuttal said.

Hasina, 60, is currently on a private visit to the US, but could be detained on her return.

That return was scheduled for April 22, but party officials said on Tuesday she might come back earlier.