The North East Scotland Pension Fund (NESPF) administers a scheme for 71,000 workers including Aberdeen, Aberdeenshire and Moray council staff.

The fund invested millions of pounds in Under Armour stock over the last few years.

It has been reported that Aberdeen City Council lawyers have accused the firm of making alleged ‘false’ statements about its products.

Aberdeen City Council is part of a class action in the US seeking damages, costs and expenses from the US company, BBC News reports.

Councillor Tauqeer Malik, convener of the council’s pensions committee, said more than £6m had been lost from the fund. He accused Under Armour of alleged “unethical practices”. However, he added that he to reassure people their pensions would be unaffected.

Mr Malik said: “The North East Pension fund has a duty and obligation to protect its pensioners, that’s why the fund has taken an action in the USA to protect its pensioners from alleged unethical practices.

“Those who rely on the pension fund should be reassured that currently the pension fund is valued a 103% which means its extremely healthy - we’re doing really well.”

When approached for a comment, Aberdeen City Council told Scottish Financial News: “As this is an ongoing legal case, Aberdeen City Council as the administering authority of NESPF will make no further comment.”

Under Armour previously said the legal challenge was “without merit” and it would defend the lawsuit “vigorously”.