The head of India's largest Tamil party was cleared of corruption Monday, in a verdict that sparked wild celebrations by supporters and paved the way for the return of one of the country's most powerful politicians.

Jayalalithaa Jayaram was forced to stand down as chief minister of Tamil Nadu after being found guilty last September of amassing illegal wealth while in office and the former film star was sentenced to four years in jail in a case that ran for nearly two decades.

But High Court judge C R Kumaraswamy declared her "appeal upheld" on Monday at a hearing in the city of Bangalore which lasted only seconds.

Although Jayalalithaa had been forced to quit as chief minister of the southern state, her return is now seen as a formality as she continued to control her party while on bail awaiting the outcome of the appeal.

The 67-year-old enjoys huge popularity in Tamil Nadu where fans know her simply as "Amma" (Mother) and ministers have been known to prostrate themselves before her.

Security was tight outside the court in Bangalore and in Chennai, the capital of Tamil Nadu, where supporters cheered, handed out sweets and set off fire crackers.

Outside Jayalalithaa's house in Chennai, hundreds of supporters held up photos of their leader and danced in the streets chanting "Amma Amma".

Party loyalists had been holding religious ceremonies in temples, praying for her conviction to be overturned.

Jayalalithaa has always dismissed the corruption charge, first brought by a rival politician in the state in 1996, as politically motivated.

She was charged in 1997, when police seized assets including 28 kilos (62 pounds) of gold, 750 pairs of shoes and more than 10,000 saris in a raid on her home.

Prosecutors said her assets, which reportedly included two 1,000-acre estates in the lush tropical state she ran, were vastly disproportionate to her earnings during her first term as chief minister, which ran from 1991 to 1996.

Jayalalithaa has earned the loyalty of many voters in Tamil Nadu with a series of highly populist schemes including an "Amma canteen" that provides lunch for just three rupees (five cents), although she has also drawn accusations of an autocratic governing style.