New Delhi/IBNS: In a setback to the Mamata Banerjee government, the Supreme Court Monday dismissed its plea against the Calcutta High Court order that transferred to the Central Bureau of Investigation (CBI) the probe into an attack on a team of Enforcement Directorate (ED) officials in Bengal's Sandeshkhali.

A team of ED officials had come under a mob attack on Jan 5 when they went to Sandeshkhali to search properties linked to local Trinamool Congress strongman Sheikh Shahjahan. 

The bench of Justice BR Gavai and Justice Sandeep Mehta also questioned the Trinamool Congress government as to why it took 50 days to arrest Shahjahan.

The now-expelled Trinamool leader is in the CBI's custody.

Besides the case relating to the attack on the ED team, the strongman and his aides face land grab, extortion, and sexual harassment charges.

Last week, the Calcutta High Court asked Bengal police to hand over Shahjahan's custody to the central agency. It had also come down heavily on the state police.

The Supreme Court Monday expunged the high court's observations on Bengal police.

In response to the apex court's query on why it took 50 days to arrest the strongman, Bengal police said a high court order had paused the investigation.

"There was a stay on investigation. We went back to court, asking for a clarification. It was clarified. Within one day, he was arrested," senior advocate Jaideep Gupta, appearing for the Bengal government, told the court.

"To say that the state police are delaying the investigation...these kinds of allegations are very damaging," he said.

The allegations by residents of Sandeshkhali, an island in Bengal's North 24 Parganas district, have raised a political storm in the state.

Shahjahan, who is at the centre of these allegations, was arrested last month after he was on the run for 55 days. What followed was a dramatic tug of war between central agencies and state police for the strongman's custody.