Tension at the top of the UK investment banking division of Investec, the South African financial services group, and disagreement over the role of corporate broking has cost it three senior bankers this week.

Jag Mundi, co-head of corporate finance, and colleague David Currie have left to join Numis Securities, a UK boutique. Mundi's boss, Russell Chambers, head of UK investment banking, has also left. A bank spokeswoman said his departure was "by mutual agreement".