Rajapaksa, who denies the charges, is widely seen as the frontrunner in the presidential election that must be held before December 9
Sri Lanka's top court on Wednesday rejected an appeal by presidential candidate Gotabaya Rajapaksa to dismiss corruption charges against him, in a possible blow to the frontrunnner's candidacy.
In a split decision, a panel of five Supreme Court judges rejected a petition by Rajapaksa, who had asked that a lower court case in which he is accused of embezzling state funds be thrown out, his spokesman said.
If Rajapaksa, 70, is found guilty in a trial, scheduled to run for three weeks from October 15, he can still appeal to the Supreme Court. But he could face a challenge to his candidacy if he were sentenced to more than six month's in jail, legal experts said.
Rajapaksa, who denies the charges, is widely seen as the frontrunner in the presidential election that must be held before December 9.
The case concerns alleged misappropriation of $187,916 of state funds to build a memorial museum for his parents in his hometown of Medamulana, 186 km south of the capital Colombo.
"It's a divided decision which shows that the Supreme Court judges are not unanimous on this," Keheliya Rambukwella, Rajapaksa's spokesman told Reuters on Wednesday. "He can appeal to the Supreme Court in the event the high court finds him guilty."
A senior lawyer familiar with the situation, who asked not to be named, said Rajapaksa could face difficulties in running if he were found guilty and any appeal had not been heard before the deadline for election nominations.
"If he is convicted of charges, then he cannot file nomination for the presidential poll," the lawyer said.
Rajapaksa, brother of former President Mahinda Rajapaksa, is immensely popular among Sri Lanka's Sinhala Buddhist majority, who credit him with ending the island nation's 26-year-long civil war in 2009.
Sri Lanka's main opposition party named the hardline former defence chief as its presidential candidate last month, seeking to capitalize on public clamour for a decisive leader following deadly Easter Day bombings claimed by Islamic State.
Rajapaksa, who previously held dual Sri Lankan and US citizenship, also faces legal challenges in the United States, where several people have sued him for his alleged role in torture and murder during the civil war.
He denies those allegations, and said last month he had renounced his US citizenship.