Still reeling from the abrupt resignation of its president last month, Peru is now captivated by a new political drama: the sibling rivalry between the children of the former authoritarian leader Alberto Fujimori, as they battle over his controversial legacy.

The power struggle between Keiko and Kenji Fujimori has all the intrigue, melodrama, plots twists and cliffhangers of an over-the-top Latin American soap opera or telenovela – and it has Peruvians hanging on the edge of their seats.

Keiko Fujimori, the leader of the majority opposition party, played a key role in the toppling of Pedro Pablo Kuczynski , as her party released a series of secretly filmed videos showing his allies offering to buy the votes of opposition lawmakers to avoid impeachment.

In releasing the videos, however, she also implicated her brother Kenji and his political allies in the alleged vote-buying, which could see him face criminal charges.

He has vowed revenge, and on Friday is due to testify to prosecutors investigating allegations that Keiko received $1.2m in campaign donations from the scandal-plagued Brazilian firm Odebrecht in 2011.

The long-simmering sibling rivalry erupted spectacularly – and now threatens to wipe out both their political futures.

Keiko, a two-time presidential candidate, tweeted her regret that “her own brother had become involved in practices which had done so much damage to us as Peruvians and as a family”. She was referring to videos which showed her father’s intelligence chief Vladimiro Montesinos bribing politicians, judges and army chiefs – which ended her father’s decade-long regime in 2000.

The former president was jailed in 2009 for authorising death squads, overseeing rampant corruption and vote-rigging. He was pardoned by Kuczynski in December, but his children could both now face criminal charges.

Ironically, the father’s pardon may have aggravated the split between the children, said Gustavo Gorriti, a Peruvian journalist who was kidnapped by Fujimori’s regime in the 1990s.

“Kenji remains completely faithful to his father and did everything possible to secure his release,” he says. “While Keiko realised it was better that he was in prison.”

Thrown into politics aged 19, Keiko became her father’s first lady in 1994 when her parents separated. Now aged 42, a seasoned politician and twice presidential candidate, she cuts a strikingly different image from Kenji, 37.

While Keiko is seen as cold and vengeful, Kenji is indulged as a spoilt youngest son, and won the highest number of votes in Congress when he we re-elected in 2016

Styling themselves as The Avengers, Kenji and a band of dissident lawmakers from his sister’s Fuerza Popular party, split the Fujimorista support base by abstaining from an impeachment vote against Kuczynski in December saving him from being ousted.

For a while the tactic worked. Kenji, a self-confessed comic-book geek depicted himself as hammer-wielding Thor or dressed in the Bruce Lee-style yellow jumpsuit of the heroine of Quentin Tarantino’s Kill Bill films.

But then, Keiko got her own back entangling Kenji and his group in the incriminating videos.

In giving evidence against his sister in the Odebrecht investigation “Kenji has shown he is prepared to go down the kamikaze way, taking his sister with him,” says Gorriti.

Facing expulsion from Peru’s congress, Kenji has lost that political capital, says Giovanna Peñaflor, director of pollster Imasen.

“By the same token, it’s been a pyrrhic victory for Keiko,” she adds, saying the dirty tactics used in the feud have worn down public sympathy for both siblings.

That has done nothing to diminish Peruvians’ fascination with the ongoing Fujimori saga, says Jorge Bruce, a psychoanalyst and newspaper columnist.

“Peruvians love telenovelas and this is a real life soap opera,” he says.

“We are a Latin American country where family is still what matters above everything else. The Fujimoris are a particularly complicated, dysfunctional family,” he adds.

“Years passed by and we are still under the spell of the Fujimori story – which says more about us than it does about them.”