Shine Lawyers have launched a class action against Westpac for allegedly selling customers life insurance policies at steep mark ups in a case they speculate could be worth $100 million.

The statement of claim filed on October 12 claims Westpac's financial planners sold term life, total and permanent disablement, trauma and income protection insurance at a 10 per cent premium compared to the same policies sold elsewhere.

The 20 page statement of claim highlights the bank's use of the code "CF 1.045" for policies that were 4.5 per cent higher and sold by its network of financial advisers. The code "CF 0.95" was used for policies that were sold at a 5 per cent discount that were available to independent financial advisers.

Westpac is the latest bank to be targeted in a class action. Carla Gottgens

Lawyers for Shine claim the bank breached its fiduciary duty, unfairly took advantage of its position and improperly used its position to gain a benefit for itself.

It is believed the policies in question were off-the-shelf will little tailoring for individual clients. Some policies were sold at a premium and some at a discount with the resulting pool of premiums the same size as another pool where all the policies were sold at 100 per cent.