India's Supreme Court has convicted Sasikala Natarajan of corruption, ending her attempts to become chief minister of Tamil Nadu.

Sasikala was an aide of chief minister Jayalalitha, who died in December.

Though she has never held public office, the ruling AIADMK party said last week that she would be the next chief minister of the southern state.

But the state was plunged into uncertainty after the acting chief minister revolted against her.

Indian law bars convicts in corruption cases from contesting an election for a period of six years after completing a jail sentence.

Tuesday's ruling against Sasikala brought a four-year jail sentence, meaning she will not be able to run for office for 10 years.

The verdict is a big blow to Sasikala who was claiming the support of a majority of Tamil Nadu's law makers to become chief minister.

She has been shut away in a resort along with more than 100 MPs for more than a week in preparation for a possible floor test. Indian media reports say police have entered the resort to arrest her.

Acting chief minister O Panneerselvam, who alleges he was forced to resign to make way for Sasikala, is likely to now stake a claim for the post.

Never given any formal role by Jayalalitha in the party or the state government, Sasikala's role was always that of aide and confidante.

But analysts say her proximity to power allowed her and her extended family to wield huge influence.

Sasikala's influence over Jayalalitha also became the source of intense media speculation and tabloid gossip.

Her appointment as chief minister elect by the ruling party had created outrage in Tamil Nadu.