Madille Pannaloka, General Secretary of the Sinhala majority nationalist group, said the complaint against Wickremesinghe has been lodged to police's terrorist investigation unit.
Wickremesinghe this week ordered the customs to release the stock of 'Frontline' magazine's anniversary edition dated February 6.
The edition carried a 1987 interview of slain LTTE chief Velupillai Prabhakaran.
"His order to release the magazine was a threat to national security," said Pannaloka.
The UN says 30,000 people were killed towards the end of the nearly three decades-long civil war in the country.
The LTTE remains proscribed in Sri Lanka and many other countries, including India, the US and the UK.
Pannaloka said: "He (Wickremesinghe) has also lifted the ban on foreigners travelling to the north and also released 1,000 acres of high security lands in the north."
"We want police to investigate".
With Wickremesinghe becoming Prime Minister in the new government of President Maithripala Sirisena, the government announced the release of private lands in the north acquired for military purposes.
The previous government of Mahinda Rajapaksa had imposed a ban on foreigners travelling to the north without prior approval.
