On his blog, Sigarchi published articles that covered the arrests of journalists in Iran, the crackdown on freedom of expression and the suppression of mourning ceremonies of the families of prisoners executed in 1989 at Khavaran Cemetery.

Sigarchi was arrested as part of a wider series of arrests in the “Bloggers” case of 2005. Initially, on January 16, 2005, Sigarchi was summoned to Branch 3 of the Revolutionary Courts of Rasht in order to provide explanations for the charges in his case. At the request of the prosecutor, Sigarchi returned to Branch 3 of Revolutionary Courts the day after these summons and his interrogation, on January 17, where he was arrested and transferred to Lakan Prison in Rasht. 

Sigarchi was charged with “cooperating in espionage activity for hostile states,” “disturbing the public mind,” “actions against national security” and “insulting the founder of the Islamic Republic of Iran [Ayatollah Khomeini] and the Supreme Leader of Iran [Ayatollah Khamenei].” The evidence that was cited to support these accusations were Sigarchi’s interviews with Radio Farda and BBC Persian.

On February 22, 2005, Sigarchi’s lawyer, Mohammad Seifzadeh, announced that Branch 3 of the Islamic Revolutionary Courts of Gilan, presided over by Judge Eskandari, had sentenced his client to 14 years' imprisonment. 

Judicial authorities set Sigarchi’s bail at 200 million tomans – high by the standards of that time.

Under a month later, on March 17, 2005, following pressure from the Iranian Journalists' Association, the Prosecutor’s Office of Gilan reduced Sigarchi’s bail to 100 million tomans. His bail was subsequently paid and he was released from prison. During his two-month detention in prison, Arash Sigarchi had been forced to spend 20 days in solitary confinement.

Sigarchi’s appeal to the lower court’s judgment was heard in Branch 1 of the Court of Appeals of Gilan, presided over by Judge Qudratullah Shamkhi, on June 9, 2005. The result of the appeal hearings was announced to Sigarchi’s lawyer on January 23, 2006. According to the court's ruling, Sigarchi had been sentenced to three years imprisonment on the accusations of “insulting the Supreme Leader” and “propaganda activities against the state” but he was acquitted of the other charges in his case.

On January 25, 2006, two days after being informed of the Court of Appeals’ verdict, Sigarchi was arrested and transferred to Lakan Prison in Rasht in order to serve his three-year prison sentence.

Sigarchi’s case was referred to the Supreme Court and his case was heard five months later, on April 29, 2006, in Branch 13 of the Supreme Court. The Supreme Court upheld the Court of Appeal’s sentence of a three-year prison term.

After less than a year in prison, Sigarchi was diagnosed with cancer of the mouth. In November 2006, he was granted medical leave and released from prison on bail for three months due to his cancer. This medical leave was extended several times. During this time, Sigarchi underwent chemotherapy and an operation in which surgeons removed half of his tongue and some of his body's lymph nodes.

Eventually, on January 10, 2008, Sigarchi traveled to the United States for medical treatment and sought refugee status there. Sigarchi is currently the digital director of the Voice of America organization.