DHAKA (AFP) -- Bangladesh's biggest political party has been wracked by a major split coinciding with the arrest of its leader and former prime minister Khaleda Zia on corruption charges, party officials said Tuesday.

The bitter tussle for power comes as emergency-ruled Bangladesh's army-backed government seeks to clean up the country's notoriously dysfunctional and dynastic political landscape before restoring democracy.
Zia, a two times former Prime Minister, was arrested along with her younger son Arafat Rahman on Monday and remanded in custody on charges of graft linked to the awarding of a multi-million-dollar government contract.
But hours before her arrest, Zia sacked the deputy leader of her Bangladesh Nationalist Party (BNP), Abdul Mannan Bhuiyan, for a ""conspiracy to split the party.""
""As the chief of the party, I cannot be a silent spectator to this type of activity,"" Khaleda Zia wrote in an expulsion letter, accusing her deputy of leading a group of so-called 'reformists' against her.
""As far as the party is concerned, Bhuiyan is no longer part of the BNP,"" Zia's aide, A.S.M Hannan Shah, told AFP.
But the sacked Bhuiyan, who is leading a rebellion with the backing of 130 former lawmakers, said his sacking was ""illegal and unacceptable"" and ""would only lead to the division of the party.""
-------Resist dynamic politics
""Our main crime was that we said we would resist dynastic politics. We wanted to get rid of the corrupt leaders within the party,"" said Ashraf Hossain, a joint secretary of the BNP who was also sacked by Zia.
The BNP was Bangladesh's last governing party, but has been in turmoil since elections were cancelled in January over opposition allegations that it had rigged the polls.
Months of crippling and often violent protests prompted the president to declare a state of emergency and the formation of an army-backed interim cabinet tasked with cleaning up one of the world's poorest and most corrupt nations.
Zia, 63, has been one of the main targets, along with her arch-rival Sheikh Hasina Wajed, another former prime minister and the leader of the Awami League. Sheikh Hasina is also behind bars facing corruption charges.
""Both Khaleda and Hasina face at least seven years in jail if the evidence of graft is proved,"" said Shahdeen Malik, a Supreme Court lawyer and professor of law at the private BRAC university.
The authorities, he said, ""seem to have strong cases against both leaders.""
Analysts said the corruption charges and BNP split were part of a major change in Bangladeshi politics, dominated in recent years by Zia and Sheikh Hasina -- or the ""battling begums"" as they are commonly known.
""The BNP is now divided permanently and it's a new reality. There is now the old and new BNP,"" said Ataur Rahman, professor of political science at Dhaka university, said.
""Sheikh Hasina's Awami League is now awaiting the same fate,"" he added.
""With Zia and Hasina in detention, both BNP and Awami League would now see splits between the reformists and the old loyalists,"" said independent analyst Nazim Kamran Chowdhury. ""It's a major realignment in our politics.