India’s highest court has granted bail to opposition leader and Delhi Chief Minister Arvind Kejriwal in a corruption case, paving the way for his release almost six months after he was arrested.

Kejriwal, a key leader in an alliance against Prime Minister Narendra Modi in elections this year, was first detained in March over a long-running corruption probe, which his colleagues described as a “political conspiracy” orchestrated by the governing Bharatiya Janata Party (BJP).

In a ruling issued on Friday, a two-judge bench of the Supreme Court said that while Kejriwal’s arrest was lawful, he should be released from custody while contesting the charges against him.

“Prolonged incarceration amounts to unjust deprivation of liberty,” Justice Surya Kant said in a verdict granting bail.

Kejriwal’s release is expected to boost the morale of his decade-old Aam Aadmi Party (AAP) as it will allow him to campaign in regional elections next month in the northern state of Haryana, where AAP is trying to make inroads.

The allegations against him stem from his administration’s decision to implement a policy liberalising the sale of liquor in 2021 and giving up a lucrative government stake in the sector.

The Directorate of Enforcement, the federal financial crimes investigating agency, accused Kejriwal’s party and ministers of accepting 1 billion rupees ($12m) in kickbacks from liquor contractors.

Kejriwal was first taken into custody in March, weeks before the general elections.

In May, the same court granted him temporary release on bail to allow him to campaign but he returned to custody once voting concluded.

Kejriwal, 55, and the AAP deny the allegations and say the cases are “politically motivated”.

In its decision on Friday, the two-judge bench, however, was split on Kejriwal’s appeal challenging his arrest, with Justice Kant holding it lawful, while Justice Ujjal Bhuyan said the timing raised serious questions.

The federal police “must not only be above board but must also be seen to remain so … in a functional democracy governed by the rule of law, perception matters,” Bhuyan said.

Outside the Supreme Court, AAP party members and allies of Kejriwal were seen celebrating, as they welcomed the court’s decision, according to posts on social media.

Manish Sisodia, an AAP member of the Delhi legislature, told reporters that the “truth has prevailed and lies have been exposed”.

Opposition parties have been demanding Kejriwal’s release, saying his arrest was an attempt by Modi’s BJP to deny them a level playing field in the polls, charges denied by Modi and the BJP.

Many countries, including the United States, had urged a “fair” and impartial trial.

The BJP said on Friday that bail for Kejriwal did not mean he was innocent.