In a letter to Temenos non-executive chairman Thibault de Tersant, Petrus - which owns just over two per cent of the core banking vendor - says: "We very much agree with Hindenburg that Andreas Andreades must finally leave Temenos".

Petrus has been calling on Andreades to leave Temenos since 2022, when he was chairman. However, rather than leave, he took on the interim CEO role when another Petrus target - incumbent Max Chuard - left in early 2023.

Hindenburg says it has uncovered the hallmarks of manipulated earnings and major accounting irregularities at Temenos. Its report knocked around 30% off the vendor's share price.

Says the Petrus letter: "Most of the points alleged by Hindenburg are based on hearsay talk from former disgruntled Temenos executives. Since 2022, we have been speaking to many of them (many of whom clearly are on a revenge mission), plus numerous Temenos customers, partners and industry experts.

"We concluded that Andreas Andreades had created a culture that favoured short-term gains over long-term value creation. Poorly executed M&A added to the problems. Investment in technology, client satisfaction and own staff had been neglected."

However, Petrus does not offer Hindenburg ("which seems to have had a bad Valentine's Day") unqualified support, and says the challenges are "not a fundamental threat to the success of Temenos" and that since late 2022, "customer and competitor feedback on Temenos’ product offering and its SaaS technology in particular has consistently improved".

Temenos has hit back at Hindenburg, stating: "The report contains factual inaccuracies and analytical errors, together with false and misleading allegations, which are intended to adversely impact the Company’s share price."

Now, Petrus is demanding that specific allegations are addressed by Monday and that Andreades be removed with immediate effect.