The media director of Sri Lanka's Ministry of Finance, Mohammed Ali Hassan, was arrested today accused of being in possession of ammunition.
Sri Lankan police reported 93 rounds of 12-bore gun ammunition were found in his possesion.
Hassan was arrested at his home in Malwana, and the area was searched by the military and police.
The arrest of a government official follows that of a Muslim Hansard officer last week, who was accused of helping one of the suicide bombers responsible for the Easter Sunday attacks.
St Anthony's Church, Colombo
Over 250 people were killed when Islamist extremist suicide bombers supportive of Islamic State detonated devices at luxury hotels and churches on Easter Sunday.
There has been increasing criticism over the government's failure to take action to prevent the attacks after it emerged India had warned Sri Lankan authorities repeatedly in the preceding weeks that such an incident was planned.
Questions have also been raised over the organisations' links with government security forces and intelligence, with reports that the intelligence authorities funded NTJ.
Earlier this month a Sri Lankan parliamentarian said the former defence secretary Gotabaya Rajapaksa gave NTJ land for an office in Colombo.
Kurunegala District UNP MP Thushara Indunil however claimed that the NTJ received support from Rajapaksa, who announced that he would the running for president in elections set to be held later this year.
Indunil said the All Ceylon Jamiyathul Ulema had warned the Sri Lankan government “as early as 2014” about the emergence of the NTJ and Islamic extremists on the island. “If the former Defence Secretary was privy to this information, we ask of what he did then, knowing the threats it posed,” he said.
“He tried to divide the peaceful community of Muslims into two. He knew that it would help him in his political endeavours which is why he strengthened one group against the other. Basil Rajapaksa said that there are 200 such mosques and the defence secretary assisted in setting them up.”
One Sri Lankan soldier is currently on the run after authorities said they believed he had taught the attackers how to use explosives.
Cabinet spokesperson Rajitha Senaratne said that at least four army officers were involved in organising the assassination of police officers in Batticaloa last year, and claimed dozens of NTJ were on the payroll of Sri Lankan intelligence linked to Rajapaksa.