An Istanbul court has issued an arrest warrant for the owner of a television channel aligned with Turkey's main opposition party on charges of bid-rigging, the prosecutor's office said late on Tuesday, Reuters reports.

The arrest warrant for Cafer Mahiroglu, owner of Halk TV, was issued as part of an investigation into an alleged criminal organization suspected of rigging public tenders by bribing public officials.

Several main opposition CHP members including district mayors were arrested under the investigation, part of a widening legal crackdown against the jailed mayor of Istanbul, President Tayyip Erdogan's main political rival, and the opposition.

Mahiroglu, a Turkish businessperson who lives in London, denied the charges in a post on X.

"I am being accused based on the fabricated false statements and slander of someone I have never met or seen in my life," he said, adding that he has been living abroad for 35 years.

"So, there is a price to be the owner of Halk TV, the people's television, and to defend democracy, rights and law."

He did not say if he would return to Turkey to contest the charges.

Istanbul Mayor Ekrem Imamoglu of the Republican People's Party (CHP), who leads Erdogan in some opinion polls, was jailed in March pending trial on corruption charges, which he denies.

His arrest triggered mass protests, economic turmoil and broad accusations of government influence over the judiciary and anti-democratic applications. The government has denied the accusations and said the judiciary is independent.

Since his arrest, authorities have detained dozens of CHP members, officials from the Istanbul municipality, and other CHP-run municipalities.