Kolkata, Aug 9 (IANS): Ridiculing the CBI over its failure to crack the Rabindranath Tagore Nobel theft case, former West Bengal minister and Saradha scam accused Madan Mitra on Monday questioned his continued detention in jail.

"Tagore Nobel theft was an international matter but the CBI within months said they won't be able to retrieve the medallion and closed the case.

"But in my case, it has been (nearly) 20 months, and I or my family or the people of Bengal still don't know what offence I have committed," said the former Trinamool Congress legislator speaking to reporters outside the court. He was arrested by the CBI in 2014 for his alleged complicity in the multi-crore rupee Saradha scam.

"I want to ask the CBI whether they find me valuable like a Nobel Prize that they continue to put me in jail," added Mitra whose judicial custody on the day was extended by a city court.

Indicted for criminal conspiracy among other offences, Mitra has been behind bars since his arrest on December 12, 2014, except for a brief period in October 2015 when he was granted bail by a lower court. The relief was subsequently cancelled by the Calcutta High Court.

Mitra's barb against the Central Bureau of Investigation comes in the wake of the Mamata Banerjee government bidding to take over the probe of the Tagore Nobel theft case.

During a recent visit to the Tagore founded Visva Bharati University at Santiniketan in Birbhum district, Chief Minister Banerjee said, given the chance her government will endeavour to retrieve the medallion.

The sensational theft of the medallion and 47 other memorabilia from Rabindra Bhawan at Santiniketan came to light on March 25, 2004.

The investigation was handed over to the CBI which after three years of fruitless probe, closed the case in August 2007, only to reopen it subsequently in September, 2008.

The agency closed the case again later.