News that Indian billionaire Gautam Adani’s empire faces U.S. fraud charges could not be timed worse for Indian Prime Minister Narendra Modi's economy.

The main opposition Congress party has accused Modi and his Bharatiya Janata Party (BJP) of shielding Adani and stonewalling independent investigations into his dealings in the country, charges the ruling party has denied. Congress workers have also held street protests demanding a parliamentary probe.

Indian opposition parties demanded a probe on Thursday into allegations of wrongdoing by the Adani Group and said they would raise the issue in parliament.