The Sri Lankan government on Tuesday began the Parliamentary Select Committee (PSC) investigation into the security lapses surrounding the Easter Sunday suicide attacks that killed 258 people including 11 Indians, despite strong objection by President Maithripala Sirisena.
President Sirisena, who is the head of the Cabinet, warned last week that he would not attend the Cabinet unless the government took immediate action to halt the parliamentary investigation.
The PSC began hearing testimony from Muslim leaders who said they repeatedly warned the authorities to dangerous radicalisation.
The committee summoned former governor of the Western province Azath Sally to testify before it.
The cabinet meeting which is usually held on Tuesday mornings was not called by Sirisena, officials said.
President Sirisena last week asked the Cabinet to halt the hearings, citing national security concerns.
Sirisena said that it was uncalled for and a serious threat to national security as the top intelligence personnel are identified through the media. He said he would not allow any serving defense official to testify before the PSC.
He wrote to Speaker Karu Jayasuriya urging a halt to the PSC.
Jayasuriya, however, replied that the PSC was a parliamentary issue and it would proceed.
Sirisena has insisted that as minister of defence and law and order he was unaware of precise intelligence warnings from India about the attack on April 21.
He suspended police chief Pujith Jayasundara and dismissed his top defence official Hemasiri Fernando after it was found that there were intelligence failures before the attacks.
Sirisena said that none of the serving officers would be authorised by him to testify in future.