The elder son and political heir of detained former prime minister Begum Khaleda Zia, was released from a prison hospital on Wednesday pending his trial on corruption charges.

Prison officials said Tareque Rahman, 43, was freed after the Supreme Court upheld his request for bail on medical grounds, which had been granted earlier by the High Court.

Tareque was arrested in March last year on 13 corruption charges, part of a sweep against endemic graft in Bangladesh launched by the country's army-backed interim government after it took over in January 2007 following deadly political violence.

Family and party sources said he would stay at the hospital for a few days before travelling abroad for medical treatment for what they say is a broken backbone.

Tareque is the senior joint secretary-general of Khaleda's Bangladesh Nationalist Party (BNP), which ruled the country for two five-year terms over the past 15 years. He is a leading aspirant in a general election due in December.

Tareque was considered one of the most influential figures in Bangladesh under his mother's government. His release makes it likely now that the BNP -- one of the two main political parties in Bangladesh -- will participate in December's elections, which would return the country to civilian rule.

Government adviser Hossain Zillur Rahman said after Tareque's release that it would pave the way for BNP's participation in the parliamentary polls.

"The process would be further eased following the release of Begum Khaleda Zia," he said without elaborating.-Reuters