Janus Capital Group, the Denver-based mutual fund firm, is facing fresh civil lawsuits in US courts over improper trading allegations a year after it reached a $226.2m (€172m) settlement with Colorado and federal regulators.

In a US Securities and Exchange Commission filing, Janus said lawsuits were filed by the attorney general's office in the State of Kansas and West Virginia and by the state of Kansas alleging market timing practices, which violated those states' laws.