Foreign Minister Mangala Samaraweera lodged a police complaint against an alleged coup attempt.
"This is a very serious matter which the government wants investigated," Samaraweera said after lodging a complaint at the Criminal Investigation Department (CID).
The new government claimed that Rajapaksa tried to remain in power by using the military to disrupt the votes counting and declaring a state of emergency.
"It has been brought to our notice that in the wee hours of 9 January there has been a serious attempt by Hon Mahinda Rajapaksa, Gotabhaya Rajapaksa, Mohan Peiris, Chief Justice, GL Peiris and one Udaya Gammanpila have been discussing and conspiring to subvert the due process of law when the results of the presidential election were becoming known," Samaraweera said in the complaint to the CID.
More From This Section
The police complaint came a day after Rajapaksa denied any coup attempt.
He said he had congratulated the winner and left his official residence Temple Trees even before the final results were announced, facilitating a smooth transition.
The probe is a fresh blow to 69-year-old former president's bid to stage a come-back after an opposition party filed a complaint against him and 11 relatives and associates, alleging massive bribery and corruption.
The JVP, or People's Liberation Front, has lodged complaints against Rajapaksa, his legislator son Namal and two brothers -- Basil and Gotabhaya.
"I received phone calls early this morning warning me to stay away from politics. I have complained to the police," he said.
Namal said his family was being subject to political mud slinging since his father's defeat.
"I will face all these false charges," Namal said.