Sri Lanka's anti-graft agency arrested President Maithripala Sirisena's chief of staff and another state official on Thursday on suspicion of accepting a bribe, officials of the agency said.

Officials of the Commission to Investigate Allegations of Bribery or Corruption (CIABOC) arrested I.H.K. Mahanama, the president's chief of staff, and P. Dissanayake, the head of the State Timber Corporation (STC), the commission said.
"Our officials arrested Mahanama and Dissanayake while accepting 20 million (rupees)," Sarath Jayamanna, the director general of CIABOC told Reuters, indicating a sum equivalent to $127,000.
Jayamanna said Mahanama and Dissanayake were remanded on until May 9 after being produced in a court.
Malik Samarawickrema, a senior minister who is in charge of foreign direct investment and the state-run Board of Investment (BOI) said the suspected corruption was an "exception".
"This is not the rule. Taking bribe is a serious issue and as far as BOI is concerned, we don't have that issue," he told reporters in Colombo on Friday.
Neither Mahanama and Dissanayake were available for comment on Friday, nor were their lawyers or other representatives.
Jayamanna said Mahanama, a former secretary of the lands ministry, had asked for a bribe of 540 million Sri Lankan rupees ($3.43 million) from an Indian investor interested in acquiring a state-owned sugar factory.
The two were arrested at a car park of a hotel in the capital, Colombo, while they were accepting 20 million rupees from the investor for the transfer of land, he said.
The President's Office said in a statement both officials had been suspended from their duties, and the president had instructed the commission to enforce the law strictly against the two without any obstruction.
The arrests come as Sirisena’s government is under heavy criticism for not fulfilling his main 2015 election pledge to eliminate rampant corruption.
The previous government was defeated in a 2015 election amid widespread allegations of corruption.
However, Sirisena's administration has taken insufficient steps to deal with the problem, his critics complain.
The government rejects such complaints saying investigations and judicial processes take time.
The governing coalition of the Sri Lanka Freedom Party (SLFP) led by Sirisena and the United National Party (UNP) of Prime Minister Ranil Wickremesinghe lost local government polls in February partly due to failure to fulfill promises to punish corrupt politicians and officials.