Image copyright Reuters

Zurich Insurance's former boss Martin Senn has killed himself, marking the second suicide among top staff at the firm in just three years.

"It is with great shock and sadness that we must inform you of the sudden death of Martin Senn. His family informed us that Martin took his life last Friday," Zurich Insurance said.

Mr Senn, who led the firm for five years, left at the end of last year.

His death comes after Zurich's financial boss killed himself in 2013.

Pierre Wauthier left a note which Zurich Insurance said referred to his relationship with the firm's chairman Josef Ackermann.

Mr Ackermann subsequently resigned, saying Mr Wauthier's family believed he was partly to blame for the tragedy.

Image copyright Zurich Insurance

His death prompted an internal investigation and an external one by the Swiss financial watchdog. Both concluded Mr Wauthier had not been put under undue stress by the firm.

Mr Senn, who was 59, left the firm in early December, just months after the insurer abandoned its plans to buy its British counterpart RSA for £5.6bn.

At the time, he acknowledged that there had been "some setbacks" but said that the company was in good shape.

Mr Senn started at the firm in 2006 as chief investment officer, and took the helm in 2010.

Zurich Insurance company employs about 55,000 people in 170 countries.