One of the six suspects, detained in connection with the attack on two visiting Indian Sikh preachers in Vienna in May, has been released due to lack of evidence.
"The man has been released because there has not been enough evidence against him to justify keeping him behind bars," said his lawyer Philipp Winkler.
Three other suspects, including the alleged mastermind of the attack in which Dera Sacha Khand leader Guru Ramandand Dass was killed and Sant Niranjan Dass was severely injured, will remain in custody for the time being, while a decision on two other suspects would be taken next week, police said.
The ringleader of the attack, who sustained a gunshot wound in his head, is in police custody in a Vienna hospital. The body of Sant Ramanand was flown back in a special chartered flight, sent by the government of India, and was cremated earlier this week.
Investigators probing the incident at Ravi Dass gurdwara near the Westbahnhof railway station on May 24, have secured over 300 pieces of forensic evidence, which means it could take months before the first results of the investigation are disclosed, police said. The incident had sparked off violent clashes in Punjab and Haryana between followers of different sects.
Four of the six offenders were Indian asylum seekers living in Austria and have been identified as Satwinder Singh, 28, Jaspal Singh, 34, Tasum Singh, 45 and Sukhwinder Singh, 28. The other two attackers -- Hardeep Singh, 33 and Charnjit Singh, 24 -- entered Austria illegally, authorities said. The men have been accused of attacking a gathering at the gurdwara with knives and at least one gun.