The CBI had not only overlooked certain crucial evidences, but also failed to identify the culprits and bring them to book as was expected of the premier agency, he said.
Demanding reopening of the case, Singh said, "For reasons best known to them", the CBI had closed the case in an unusually hurried manner." It raised several questions on the CBI's handling of the case, he added.
Many aspects of the case, including financial transactions and linkages with foreign entities, had been conveniently ignored in the probe, the Chief Minister said.
The CBI had also not identified and questioned certain key witnesses or suspects whose examination could have shed light in the case, Singh added.
In November 2015, the previous government had handed over to the CBI the investigation of three sacrilege cases.
The CBI filed the closure report on July 4, giving clean chit to the accused in the 2015 Bargari sacrilege case. The agency had rejected the findings of the Punjab Police special investigation team in the case.
The Chief Minister said the CBI was controlled by the central government, which is led by the Bharatiya Janata Party (BJP), an ally of the ruling Shiromani Akali Dal (SAD) at the time of the sacrilege incident.
The needle of suspicion in the Bargari case had been pointed at the SAD by the Justice Ranjit Singh (retd) Commission, he said and added, given this the CBI decision to file closure report was highly questionable.
The CBI decision to file the closure report had pained not just Sikhs in India and but also the large Sikh diaspora abroad, he added.
( With inputs from IANS )