US authorities are investigating Deutsche Bank’s asset-management arm, DWS Group, after the firm’s former head of sustainability said it overstated how much it used sustainable investing criteria to manage its assets, according to people familiar with the matter.

The probes, by the Securities and Exchange Commission and federal prosecutors, are in early stages, the people said. Authorities' examination of DWS comes after The Wall Street Journal reported that the $1tn asset manager overstated its sustainable-investing efforts. The Journal, citing documents and the firm's former sustainability chief, said the firm struggled with its strategy on environmental, social and governance investing and at times painted a rosier-than-reality picture to investors.