SYDNEY—Australian blogger Yang Hengjun, who is facing trial in Beijing for alleged espionage charges, has asked the judge to exclude evidence obtained during interrogations in which he says he was tortured, according to a message conveyed to family and friends. In his first comments since Thursday’s court hearing, which was closed to family and Australian consular officials because China says it involved state secrets, Yang also expressed concern that geopolitical tensions may influence the outcome of his trial. “If a wrong decision is made because of political pressure or bad international relations, under the pretext of national security, that’s bad,” he said in the message, which was seen by Reuters and verified by a source with knowledge of the matter. Diplomatic ties between Australia and China have deteriorated sharply since Yang was detained in January 2019, with China imposing trade sanctions on some imports from Australia and reacting angrily to …