The 324 members of the assembly cannot vote on binding laws, but recommend that countries make democratic reforms and defend human rights. While the institution has a low profile, it has been credited with pressuring countries to abolish the death penalty, as well as helping the former Soviet-bloc countries transition to democracy.

Last year, after receiving complaints that lawmakers had helped silence criticism of the country’s record on human rights and the rule of law, the assembly ordered an investigation into its members’ activities in Azerbaijan.

Three former European judges led the 10-month inquiry, and their findings, released two weeks ago, highlighted cases of conflicts of interest and corruption involving about a dozen former and current lawmakers. The investigation concluded that the officials had benefited from helping Azerbaijan dodge criticism from the European assembly in its reports on countries and some of its votes.

“Corruption is one of the most widespread and insidious of social evils,” the 291-page report concluded. “The parliamentary assembly of the Council of Europe has not been spared that scourge.”

Mr. Samuelsen highlighted the case of Mr. Agramunt, who is a senator representing the Popular Party of Prime Minister Mariano Rajoy of Spain. In a radio interview last week, Mr. Agramunt, 66, said he had been threatened with blackmail by a Ukrainian lawmaker who claimed to have photos of him “with ladies.”

Mr. Agramunt jokingly told the Spanish radio station, Cadena Ser, when asked whether he had slept with prostitutes in Azerbaijan, that he would have been happy to share such photos with his friends if they had existed, but that he was too old for such activity.

Mr. Agramunt later apologized for his comments about prostitutes.

Like other lawmakers named in the report, he denied any wrongdoing, telling Cadena Ser that the former judges’ report was filled with “accusations, comments and rumors made anonymously and with neither proof nor evidence.”