An Indian court on Saturday convicted Jayalalithaa Jayaram, a former film star who became one of the country's most colourful and controversial politicians, in a corruption case that has dragged on for nearly two decades.

The chief minister of the prosperous southern state of Tamil Nadu was charged with amassing illegal wealth 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 was found guilty of "amassing wealth disproportionate to known sources of her income," prosecutor G. Bhavani Singh told reporters outside the makeshift court in the southern city of Bangalore where she was convicted.

Singh said the judge may sentence Jayalalithaa later Saturday and that she could face up to seven years in jail.

But Indian media speculated that Jayalalithaa, who runs the third largest party in India's national parliament, would have to resign as chief minister after the verdict regardless of the sentence.

Hundreds of party loyalists had come to Bangalore to show support for their leader, and many were in tears after the verdict.

"She will come out victorious, she will come out stronger," one supporter told NDTV news channel.

The 66-year-old politician enjoys huge popularity in Tamil Nadu, a manufacturing hub, where she is known to her fans simply as "Amma" (Mother).

Her AIADMK (All India Anna Dravida Munnetra Kazhagam) party emerged as third biggest force in the national parliament after winning 37 of the 39 parliamentary seats in the state in this year's general election.

Police on alert

Jayalalithaa and her supporters have always maintained that corruption charges against her were political motivated.

She has earned the loyalty of people in the southern state 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.

Her comments during the election campaign that it was time for a change in New Delhi raised speculation that her party could act as kingmaker to Prime Minister Narendra Modi, although in the end, his Bharatiya Janata Party (BJP) won an outright majority.

Nevertheless, she is regarded as an ally of the prime minister, and her conviction will come as a blow to the government.

Jayalalithaa took over the leadership of the AIADMK party after the death of its founder M. G. Ramachandran -- her on-screen love interest in multiple movies.

She is now on her third term as chief minister of Tamil Nadu, where she draws massive support, and police were on high alert for protests after Saturday's verdict.

Three close associates of Jayalalithaa were also found guilty of corruption, Singh said.

All four defendants were present when the judge delivered the verdict in a makeshift courtroom set up at the main jail in Bangalore, India's southern technology hub.

The case was held in Bangalore rather than Tamil Nadu for security reasons and there was a heavy police presence as the verdict was delivered, with authorities fearing clashes between rival political supporters.