Ms Jayalalitha was convicted and sentenced for four years by a trial court in September.

She was found guilty of amassing unaccounted-for wealth of more than $10m (£6.4m) and had to quit as the chief minister.

Monday's ruling means she can return as the head of Tamil Nadu government.

Jayalalitha, a former actress, is one of India's most controversial and colourful politicians. She has been a leading figure in south Indian politics for three decades.

As soon as the high court in the southern state of Karnataka announced its verdict on Monday morning, Ms Jayalalitha's supporters began celebrating outside the court in Bangalore.

Her supporters outside her home in the southern city of Chennai were seen distributing sweets, shouting slogans and weeping tears of joy.

The high court also cleared three of her aides who were also convicted by the trial court.

The details of Monday's judgment are not yet available. Reports from the courtroom said the judge took "10 seconds" to deliver the verdict.

The conviction last September had cut short her fourth term as the chief minister of Tamil Nadu and she had picked party leader and loyalist O Panneerselvam as her replacement.