Two executives from Amsterdam Port Services (APS) arrested in connection with the Probo Koala toxic waste scandal were released on Friday but remain suspects...APS is the processing firm that was initially commissioned to clean up the ship's chemical waste. The two men are suspected of breaking regulations concerning...waste materials, contravening pollution laws and falsifying documents...According to...[APS's] spokesman, the two men had only been questioned by police...An arrest warrant has also been issued for the ship’s captain who is currently abroad. Trafigura, the Amstelveen registered owners of the Probo Koala, is also under investigation and documents from the company have been seized...Trafigura and...Ivory Coast...have...reached a €152m settlement.