A private equity group based in London risks becoming caught up in the Kenyan political crisis after the country’s opposition leader called for a boycott of a bank in which it is the largest shareholder.

Helios Investment Partners paid KSh11bn ($176m) for a 25 per cent stake in Equity Bank days before a presidential election in which Raila Odinga, opposition leader, claims he was robbed of victory by government-orchestrated rigging.