Shares of all 10 group and related companies also fell over 5% in early trading in India, with Adani Total Gas leading the decline.

Bond prices fell, resulting in a 38 basis points increase in the yield on a note from Adani Ports & Special Economic Zone due in February 2032 to 7.20%. The yield had jumped 54 bps to 7.36% earlier in the day, marking the biggest single-session gain since February.

The daily decline on most actively traded dollar bonds was the largest in six to 12 months.

US investigators are probing whether an Adani entity, or individuals associated with the company, including Gautam Adani,

were involved in paying officials in India for favorable treatment on an energy project, Bloomberg reported on Friday.

The group did not immediately respond to Reuters' request for comment.

A report by U.S. short seller Hindenburg Research in January of last year triggered a sell-off in stocks and overseas listed bonds of Adani Group companies. The group has denied all wrongdoings.

Since then, most of the group's foreign bonds and domestic shares have rebounded above the levels they traded at before the Hindenburg report was issued.

(Reporting by Bhakti Tambe and Hritam Mukherjee; Editing by Dhanya Ann Thoppil)