In January, Siddiq resigned as a government minister following pressure because of her ties to her aunt.
A court in Bangladesh sentenced the niece of ousted Prime Minister Sheikh Hasina to two years in prison in absentia on Monday for her alleged role in corruption connected to a government land project.
Rabiul Alam, the judge of Dhaka's Special Judge’s Court, said former Labour MP Tulip Siddiq was guilty of corruptly influencing her aunt in helping her mother and two siblings get a land plot in a government project.
Hasina was charged with misusing her power as prime minister and sentenced to five years.
Siddiq's mother, Sheikh Rehana, was given seven years in prison and was considered a prime participant in the case.
The judge also fined the three $813 (€700) each and ordered the cancellation of the allotted plot for Rehana.
There are 14 other suspects.
Khan Mohammed Mainul Hasan, the corruption watchdog's prosecutor, said they had sought life in prison for the prime defendants.
"We expected life sentences, (but) that did not happen. We will consult with the commission for our next course of action," he said.
Siddiq, who represented London's Hampstead and Highgate areas in the UK Parliament, had earlier denied the allegations and said the trial was a farce built on "fabricated accusations and driven by a clear political vendetta."
She is unlikely to serve the sentence.
In January, Siddiq resigned as a government minister following pressure because of her ties to her aunt.
Hasina was sentenced to death in November for crimes against humanity involving the crackdown on the mass uprising that ended her 15-year rule last year. She currently lives in exile in India and all of her trials have been conducted in absentia.
The country is now run by an interim government headed by Nobel Peace Prize laureate Muhammad Yunnus who declared the next parliamentary elections will be held in February.
Hasina and the others in the case decided Monday did not appoint any defence lawyers to represent them.
Rehana is staying outside the country and Siddiq's two siblings are also abroad as they face other charges involving last year's uprising.