The Sri Lankan government said on Sunday that it has sought assistance from India, the United States and Britain to help investigate financial fraud allegations against the former government.

Prime Minister Ranil Wickremesinghe said Foreign Minister Mangala Samaraweera and Justice Minister Wijeydasa Rajapaksa had visited these countries to seek assistance from institutions for the probe.

"We have sought assistance from the World Bank, the U.S. Justice Department, the major fraud investigations unit in London and the Indian Central Bank," he said.

The prime minister said the government was blamed for failing to arrest former government officials over corruption.

However, he stressed no one should be arrested without enough evidence at hand.

"This is not like investigating a murder. We need time," he said, adding that the government expected a major part of the investigations be finished by April 23.

The new government, which came into power following elections in January, had set a 100-day deadline to complete constitutional reforms, probe corruption and offer relief to the public.