The head of Indonesia's election commission has been arrested on suspicion of involvement in a multimillion-dollar kickback scandal.
Nazaruddin Sjamsuddin rejects claims he received kickbacks
Nazaruddin Sjamsuddin is the fourth official to be arrested amid claims that firms supplying equipment for last year's presidential poll paid bribes.
He rejects the charges, saying he thought $45,000 (£25,000) he received was to pay legitimate expenses.
Indonesia has witnessed a series of high-profile anti-graft investigations.
President Susilo Bambang Yudhoyono won power last year promising to tackle graft in Indonesia, consistently ranked as one of the world's most corrupt countries.
The BBC's Rachel Harvey in the capital, Jakarta, says Mr Sjamsuddin's arrest is likely to be seen as evidence that the government is serious in its pledges.
Investigators from the anti-corruption commission detained Mr Sjamsuddin at about midnight and took him to a police cell.
The head of the unit investigating the case, Tumpak Hatorangan Panggabean, said Mr Sjamsuddin admitted receiving $45,000 from firms that won contracts related to the holding of Indonesia's elections last year.
Mr Sjamsuddin then took investigators to his home and returned the money, less $100, Mr Panggabean said, according to the Reuters news agency.
"The civil servant received the funds, which came from the suppliers of goods and services to the election commission, and which it is suspected were given because of the power or authority related to his position as chairman," Mr Panggabean said.
A lawyer for Mr Sjamsuddin, Josef Badioda, told Reuters that his client admitted possessing the money but believed it was legitimate funds he could use for things such as travel expenses, paying his aides and his driver.
Irregularities within the election commission came to light last month and investigations revealed that private companies paid about 20bn rupiah ($2.1m; £1.1m) to ensure contracts to supply ink, ballot papers and ballot boxes for the presidential and parliamentary elections.
Our correspondent says the scandal has cast a shadow over the commission, which had been praised for its handling of the polls.
But she says it also enhances the standing of the anti-corruption body.