Chennai:  Wherever Jayalalithaa was, her somewhat shadowy friend Sasikala Natarajan, 59, would almost always hover in the background.

She would be on the backseat of the AIADMK leader's car and campaign van, on the balcony of the Assembly during an important discussion, and in the front row at the party's general council.

Apparently, Jayalalithaa never took any big decision without seeking Sasikala's advice. The friends lived under the same roof for over three decades, Sasikala staying away from her husband whom Amma had pronounced persona non grata.

Sasikala had been introduced to Jayalalithaa in the 1980s as someone who would lend her movie cassettes from her video shop. She soon wormed her way into the leader's heart.

She first helped Jayalalithaa with the management of her sprawling bungalow while her husband Natarajan, a government PRO, looked after Jayalalithaa's appointments, especially after MGR's death.

Jayalalithaa booted Natarajan out, suspecting that his political ambitions would derail her own future. But Sasikala struck a close emotional rapport with her.

During the Mahamaham festival in Kumbakonam in 1991, the two friends poured holy water on each other, unmindful of a stampede on the other side of the temple tank in which 70 people died.

In 2008, when Jayalalithaa celebrated her 60th birthday and visited a famous temple, she and Sasikala were garlanded together by the shrine authorities - a welcome usually reserved for married couples.

Just as Jayalalithaa's control over the party was unquestioned, so was Sasikala's influence on Amma. So much so that Jayalalithaa adopted Sasikala's nephew as her foster son and married him off in a lavish ceremony.

Another of Sasikala's nephews was made an MP and the party treasurer for a while. Several other Sasikala relatives occupied key party posts and drew accusations of using their clout to grab properties through threats and coercion.

"There was a time in 2004 when nearly 100 relatives, close and distant, of Sasikala were running amok in the state with AIADMK leaders and officials at their beck and call," recalled a senior lawyer, once their legal adviser.

The group was known as the "Mannargudi Mafia" after Sasikala's ancestral town.

When the DMK targeted Jayalalithaa in the wealth case that sent her to jail two years ago, it also prosecuted Sasikala and two of her relatives. All four were convicted.

"Sasikala's nephews used to travel on mopeds in the late 1980s but in the next five years they were driving imported cars," a former AIADMK minister recalled.

In the Tansi land acquisition case that unseated Jayalalithaa as chief minister for a while in 2001, she and Sasikala had been co-accused as they were business partners.

The huge Kodanadu estate, where Jayalalithaa used to holiday regularly, had been bought in both their names.

Jayalalithaa twice reluctantly threw out her friend: when the party split in 1996 because of Sasikala's power-mongering, and in 2011 when she got fed up with the Sasikala clan's exploitation of their power.

Each time she gave in within months or weeks and took her back. Sasikala's stranglehold on Jayalalithaa's mind as well as her home, party and government remained unshakeable.

In 2014, as the duo awaited the court verdict in the wealth case, another nephew of Sasikala took control of a multiplex in Chennai, again through dubious means, underlining the family's undiminished avarice.

Over the past two years, as Jayalalithaa was hamstrung by her failing health, Sasikala and her family members converted their influence into direct command over the state's power structure. Even the physician leading Jayalalithaa's medical team happened to be a relative of Sasikala.

Asked whether Sasikala's influence, which derived directly from her proximity to Jayalalithaa, survive Amma's passing, an AIADMK senior said it would but "only for a short while".

"She is no leadership material but only a backroom operator. Preserving the Jayalalithaa legacy for any length of time would require direct communication with the cadre and the public," he said.

"Once the regional leaders start asserting them, Sasikala would be reduced to another factional leader in the party before it starts disintegrating."