MANILA — A Philippine senator who had been the leading domestic critic of President Rodrigo Duterte and his bloody antidrug campaign was arrested Friday on charges that she took bribes from imprisoned drug traffickers.

The senator, Leila de Lima, has denied the charges, describing them as political persecution. A Philippine court ordered her arrest on Thursday, and she went home Thursday night to say goodbye to her family.

Speaking to journalists on Friday before she was led away, Ms. de Lima was combative. “These are all lies,” she said of the charges. “The truth will come out at the right time. If they think they can stop me from fighting these daily murders, they are wrong.”

Ms. de Lima has been a fierce opponent of Mr. Duterte’s crackdown on users and sellers of narcotics, under which thousands of people have been killed by the police or by vigilantes since Mr. Duterte took office in June. Last year, a Senate panel led by Ms. de Lima heard testimony from a professed hit man, Edgar Matobato, who said he belonged to a death squad that had been overseen by Mr. Duterte when Mr. Duterte was mayor of Davao City.