When influential tech investor SoftBank backed Wirecard last year, it gave a $1bn jolt to the German fintech firm, and temporarily quieted questions about the legitimacy of its profits.

Wirecard’s rapid unravelling last month in an accounting scandal is bringing new scrutiny to the deal. SoftBank lent its name and reputation to the digital-payments company, but offloaded the financial risk to other investors. Mutual funds and pension funds that bought Wirecard bonds are sitting on massive losses.