Dhaka, March 16 (IANS): Former Bangladesh prime minister Khaleda Zia was ordered on Monday to appear before a trial court on April 13 in a coal mine graft case.

A Dhaka court issued the order for the Bangladesh National Party (BNP) chief and 15 others involved in the Boropukuria coal mine graft case, bdnews24.com reported.

Khaleda and the 15 others are accused of causing the state exchequer a loss of about 1.59 billion taka (about $20 million) by signing a deal with the China National Machinery Import and Export Corporation (CMC) to operate, manage, and maintain the Boropukuria coal mine.

The High Court on October 16, 2008, stayed the case proceedings for three months following a petition by Khaleda seeking the quashing of the case.

It also issued a rule asking why the case should not be dismissed.

The Appellate Division later upheld the stay order leaving the corruption case in the cold.

Khaleda, however, had secured a permanent bail in the case on January 15, 2012.