Ilya Yashin, one of the Russian opposition politicians traded to the West in Thursday’s prisoner exchange, expressed outrage on Friday that he had been sent into involuntary exile rather than left in his own country, even if that meant remaining in prison.

“I will never make peace with the role of an emigrant,” Mr. Yashin, 41, said at a news conference with other dissidents in Bonn, Germany.

He described a statement he wrote before he was moved from his penal colony, insisting that he did not consent to be exchanged, which he said included the declaration, “The Russian Constitution bans sending a citizen of the Russian Federation abroad without his consent. As a Russian citizen, I confirm that I do not give permission to be sent outside of Russia.”

He said he was told that if he attempted to return, he would meet the same fate as Aleksei A. Navalny, the opposition leader who died in February in the Arctic penal colony where he was serving several sentences on what Western governments and human rights groups said were trumped-up charges.

Moreover, Mr. Yashin said, “They made it clear that my return would block any potential exchanges of any other political prisoners.” He said that there were many in far poorer health that should have taken his place in the exchange.

“It is unbearable to think that I am free because I was exchanged for a killer,” said Mr. Yashin, referring to Vadim Krasikov, a Russian convicted by a German court of murdering a former Chechen separatist fighter in central Berlin in 2019. After he was returned to Moscow, the Kremlin acknowledged that Mr. Krasikov was an operative of the F.S.B., one of the Russian intelligence agencies that grew out of the Soviet K.G.B.