Vodafone and O2 plan to continue their business relationships with German MVNO Drillisch despite rival operator Deutsche Telekom suing the company, reports Reuters.

Deutsche Telekom filed criminal charges against Drillisch on Monday as it suspects its Simply subsidiary, which sells pre-paid mobile contracts running on Deutsche Telekom’s network, has committed commission fraud.

According to press agency Dpa, Deutsche Telekom found that 30,000 pre-paid SIMs were activated by Simply in February without an underlying customer relationship. This meant the Drillisch subsidiary received provisions under false pretences. Deutsche Telekom has requested payback of EUR1.3 million although Drillisch denies the allegations.

An O2 spokesman told Reuters that as far as the company is concerned, Drillisch has been a reliable partner. Vodafone noted that it hadn’t noticed anything suspicious during the time it has dealt with the MVNO.

Shares in Drillisch almost halved following Deutsche Telekom’s statement on Monday, to hit their lowest level in two years, according to Reuters, although they partially recovered on Tuesday. Financial analysts said the impact of the fraud charges is likely to be limited in light of the positive comments by Vodafone and O2.