JAKARTA (AFP) - The deputy chief of Indonesia’s most powerful anti-corruption body was arrested Friday over allegations he interfered in a legal case, police said, sparking protests outside the agency headquarters. The shock arrest of Bambang Widjojanto, second-in-charge at the Corruption Eradication Commission (KPK), comes about a week after the agency accused a high-ranking police general of corruption, postponing his appointment as the country’s new police chief. National police spokesman Ronny Sompie said Widjojanto, who was being questioned at police headquarters in Jakarta, could face seven years in prison if found guilty of the allegations. The arrest has drawn criticism that the police are trying to hinder a government clampdown on corruption in Indonesia, which new President Joko Widodo has made a cornerstone of his leadership. Mr Widodo also urged the national police and the KPK to avoid “friction" after the arrest sparked an outcry. Hundreds of activists gathered for a noisy protest outside the KPK headquarters in Jakarta, claiming Widjojanto’s arrest for allegedly interfering in a legal case was police acting out of revenge.Indonesia’s millions of social media users called on Widodo, who made combating corruption a cornerstone of his leadership, to speak out with #WhereAreYouJokowi just trailing #SaveKPK as the top mentions on Twitter. The president, speaking after meeting with the KPK chairman and deputy police chief, urged both parties to act objectively. “As head of state I also asked the national police and KPK not to let friction occur when performing their duties,” Widodo told reporters. Earlier national police spokesman Ronny Sompie said Widjojanto was accused of ordering witnesses to give false evidence during a 2010 constitutional court challenge to a local election result, Sompie added.Sompie said Widjojanto was accused of ordering witnesses to give false evidence during a 2010 constitutional court challenge to a local election result. “We have enough strong evidence of his suspected involvement in the case,” he said. “We don’t know yet whether he will be detained after questioning or not. It all depends on today’s questioning.”Sompie insisted the investigation was focused on Widjojanto and unrelated to the KPK, an institution that has butted heads with police in the past. The KPK this month launched a corruption investigation into three-star general Budi Gunawan, who just days earlier had been named the sole pick for national police chief by Widodo. The president refused to revoke Gunawan’s nomination, but later postponed his appointment until the KPK investigation was complete. The news of Widjojanto’s arrest sparked a protest by anti-corruption activists outside KPK headquarters. Demonstrators accused the police of trying to criminalise the fight against corruption, arguing that it was retaliation for the Gunawan case. Indonesia Corruption Watch in a statement called the arrest “a fight by the national police against the KPK” and urged Widodo to step in. Widjojanto was widely seen as a clean figure in a nation that has seen its share of high-profile graft cases. Anti-corruption group Transparency International ranked Indonesia 107th out of 175 countries in its annual corruption perceptions index last year. A number one ranking means the least corrupt.