He was born on 22 January 1958. He passed the High School Leaving Certificate Examination from the Don Bosco High School, Guwahati in Assam. Later he earned a Bachelor of Commerce degree from the Gauhati Commerce College, an affiliated college of Gauhati University.
He also pursued a law degree (LL.B.) from the University College of Law, of the University of Calcutta. He would later enroll as an Advocate on 13 February 1984. he practised in civil and constitutional matters in both the Original side and Appellate Side of the High Court at Calcutta and was elevated as a permanent Judge of the High Court at Calcutta on 3 December 2003.
Justice Sen has been bearing the allegation for appropriating Rs 32 lakh as a court-appointed receiver in 1993 in a lawsuit between Steel Authority of India Limited (SAIL) and Shipping Corporation of India over supply of fire bricks.
The Chief Justice recommendation was made shortly after a three-judge inquiry committee had established Sen's misconduct in depositing the money in his personal account. Sen retained the money even after being appointed as the High Court judge in 2003. It was in 2006 after HC order, he returned money.
Justice Sen was held guilty of misappropriation of public funds he received in his capacity as receiver appointed by the High Court of Calcutta and misrepresenting facts with regard to it by a committee of three judges set up by former CJI K. G. Balakrishnan in 2007. A year later, Justice Balakrishnan recommended his impeachment to the PM, after which a legal opinion obtained by the law ministry endorsed the judges' committee report.
In 2009, 58 MPs of the Rajya Sabha moved a motion for impeachment of Calcutta High Court Judge Soumitra Sen for his involvement in financial misappropriation. Probe panel was set up by Rajya Sabha chairman Hamid Ansari in February 2009. It was headed by SC judge Justice B Sudershan Reddy and had as its members Punjab and Haryana High Court Chief Justice Mukul Mudgal and noted Jurist Fali S. Nariman. The Committee said the charges were duly proved.
The report of the three-member committee, placed in both Houses of Parliament, said it was of the opinion that Justice Sen was 'guilty of misbehaviour' under Article 124(4) read with proviso (b) to Article 217(1) of the Constitution of India.
Article 124(4) when read with proviso (b) to Article 217(1) states that a judge of a high court shall not be removed from his office except on the grounds of 'proved misbehaviour'. The prefix 'proved' only means proved to the satisfaction of requisite majority of Parliament, if so recommended by the inquiry committee.
The report said the oral and documentary evidence had established that two separate accounts were opened by Justice Sen as "receiver" in his own name and a total sum aggregating to Rs 33, 22, 800 being the sale proceeds of goods were brought into the two accounts between 24 March 1993 and 5 May 1995.
The indictment of Sen paved way for Parliament to take up the impeachment of the judge who had been found guilty of collecting Rs 33,22,800 from a purchaser of goods, keeping it in a savings bank account and misrepresenting facts to the high court.
Subash Bhattacharya the lawyer of Justice Soumitra Sen said that his client is innocent and he will prove he is innocent. As per the Judges Inquiry Act, the motion was moved in the Rajya Sabha and debated upon. Sen was given an opportunity to defend himself through his counsel. On 18 August 2011, Rajya Sabha passed the impeachment motion by overwhelming majority of 189 votes in favour and 17 against.
This is the second case in the history of the country in which Parliament has initiated proceedings for removal of a judge. The first involved Justice V. Ramaswami.
Ahead of the impeachment motion against him in the Lok Sabha on 5 & 6 September 2011, he resigned on 1 September 2011. In his resignation letter he said that, "Since the Rajya Sabha has decided in its wisdom that he should not continue as a judge, he has decided not to go to the Lok Sabha, and put in his papers instead." Later, Lok Sabha decided to drop the impeachment proceedings against him because he had resigned.
On 15 Jan 2012, it became public through an RTI query that Justice Sen along with his other colleague facing similar accusations Justice P. D. Dinakaran will keep getting their post-retirement benefits, even though they resigned ahead of impeachment proceedings against them, as there are no Constitutional or statutory provisions restricting their entitlements in such a scenario.
- P. D. Dinakaran - former High Court Chief Justice against whom Parliament initiated impeachment proceedings.
- V. Ramaswami - former Supreme Court judge who became the first judge against whom Parliament initiated impeachment proceedings.
- "Rajya Sabha Approves Impeachment of Justice Sen". 18 August 2011. Archived from the original on 31 January 2013. Retrieved 23 March 2012.
- "Justice Sen faces impeachment in Rajya Sabha". DNA india. 17 Aug 2011. Retrieved 23 March 2012.
- "Soumitra Sen resigns, saves embarrassment". The Pioneer. 2 September 2011. Retrieved 16 January 2012.
- "Justice Sen escapes impeachment". The Pioneer. 5 September 2011. Retrieved 16 January 2012.
- "Dinakaran, Sen to get retirement perks". 15 Jan 2012. Retrieved 16 January 2012.