COLOMBO (Reuters) - Sri Lanka’s controversial former defense secretary Gotabaya Rajapaksa has launched legal proceedings to renounce his U.S. citizenship, he said on Friday, ahead of a probable candidacy in a presidential election.

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Gotabaya, brother of former president Mahinda Rajapaksa, oversaw the crushing of Tamil Tiger rebels a decade ago, but has faced accusations of war crimes, including extra judicial killings.

Soon after his return from a trip to the U.S., Gotabaya, who has citizenship of both the United States and Sri Lanka, told reporters he had begun the process with U.S. authorities.

“I went to the U.S. to initiate the legal process to renounce my U.S. citizenship. I have done it successfully,” said Gotabaya, who was welcomed home by hundreds of supporters gathered at the airport.

His spokesman, Milinda Rajapaksha, said Gotabaya was considering plans to run for president later this year.

But a possible obstacle to his political ambitions could prove to be lawsuits filed by activists seeking compensation for his alleged role in the civil war.

Gotabaya has rejected the accusations, ascribing a political motive to them.

The South Africa-based International Truth and Justice Project, in partnership with U.S. law firm Hausfeld filed a civil case in California this week against Gotabaya on behalf of a Tamil torture survivor.

In a separate case, Ahimsa Wickrematunga, the daughter of murdered investigative editor Lasantha Wickrematunga, filed a complaint for damages on April 4 in the same U.S. District Court in California for allegedly instigating and authorizing the extrajudicial killing of her father.

“I have been in the U.S. more than ten times. But these people never asked me for compensation. So this is done ahead of the presidential poll,” said Gotabaya.

Gotabaya and his brother Mahinda have rejected calls for an international probe into alleged war crimes in the final phase of the 26-year war.