Defying international condemnation and rejecting 11th-hour pleas for clemency, the Indonesian government executed eight drug convicts after midnight on Wednesday, including seven foreigners.

However, minutes after their execution, families of the departed have opened another dimension in the drama, alleging that the judges offered to give light sentences in lieu of bribe. Lawyers for Mr. Chan, 31, and Mr. Sukumaran, 34, say the judge who handed down the death penalty to the pair had offered a lighter sentence in exchange for money. The pair, members of the so-called Bali Nine who were arrested in 2005 trying to smuggle 18.5 pounds of heroin out of the resort island, admitted guilt but said they had reformed.

The Indonesian wife of one of the Nigerians executed, Silvester Obiekwe Nwolise, 47, also claimed that the judges at his trial had offered a lighter sentence in return for a bribe.

Another Nigerian who was executed did not have a lawyer when he tried to appeal his death sentence, while the Brazilian convict, Rodrigo Gularte, 42, had had schizophrenia and bipolar disorder since he was a teenager, conditions that his lawyers say should have disqualified him from criminal prosecution under Indonesian law.

But the execution of a ninth convict, scheduled to happen at the same time, was unexpectedly postponed at nearly the last minute, according to the Indonesian attorney general’s office.

The executed prisoners, from Australia, Brazil and Nigeria, along with one Indonesian, were shot by police firing squads about 12:25 a.m. local time at a site outside the gates of Pasir Putih prison on the island of Nusa Kambangan off the southern coast of Java, according to the attorney general’s office.

The authorities granted the stay of execution to Mary Jane Veloso, 30, a Philippine citizen, after the Philippine government requested her assistance in a human trafficking case involving a woman who surrendered to the Philippine police on Tuesday.

“An alleged perpetrator of human trafficking gave herself up, and Mary Jane’s testimony is needed,” Tony Spontana, a spokesman for the Indonesian attorney general, wrote in a text message shortly after the executions were carried out. “Eight people were executed, but not Mary Jane,” he wrote.

Ms. Veloso’s family maintains she was duped by a drug syndicate into flying to Indonesia in 2010 with more than five pounds of heroin hidden in a suitcase. President Benigno S. Aquino III of the Philippines had repeatedly appealed for her to be spared. The woman who surrendered to the Philippine police on Tuesday was identified as one of those who had recruited Ms. Veloso.

Relatives and friends of the condemned paid them final visits on Tuesday but were not allowed to witness the executions.

Shortly after midnight Tuesday, mourners in the port town of Cilacap, which is the access point to the prison island, held a vigil for the condemned prisoners that was televised.

The mass execution was the second in Indonesia this year. In January, five foreign drug convicts and one Indonesian convicted of murder were shot by firing squads on the island.

On Saturday, the attorney general’s office gave 72 hours’ notice to the latest group of condemned prisoners, their legal teams and their respective embassies that the executions would be carried out. On Monday, an Australian prisoner, Andrew Chan, married his Indonesian fiancée in a small ceremony at the prison.

A French citizen who was also originally on the list to be executed won a two-week reprieve from the State Administrative Court in Jakarta, the Indonesian capital, which will hear his challenge to a clemency rejection by President Joko Widodo.

Shortly after taking office last October, Mr. Joko declared that Indonesia was facing “a national emergency” of drug abuse, and he rejected 64 clemency appeals from death row drug convicts, most of them foreigners. Saying Indonesia had a right to exercise its drug laws, Mr. Joko’s government rejected international pleas to cancel the executions, including from Ban Ki-moon, secretary general of the United Nations.