Sunho Biologics (HKG:2898) said it had formed a board committee to independently investigate a matter of upfront payments to certain service providers during the second half of 2025, according to a Tuesday filing with the Hong Kong bourse.

Trading in the company's shares has been suspended since April 1, and will remain halted until further notice.

The firm previously announced a delay in the publication of its 2025 annual results to give its auditor time to collect documentation and information relating to the service agreements.

The matter stems from the upfront payment of $15.3 million to four service providers in exchange for advisory services during the second half of 2025.

Given "current market uncertainties," the firm said it had "adjusted" its business development and capital market strategies and cancelled the service agreements for a full refund of the amounts paid.

However, the firm said it was investigating the matter from a corporate governance perspective to identify internal control issues in connection with the payment.