"To confirm the rumours" means to verify or validate information or stories that are circulating among people, and to ensure that they are true and accurate. Full definition
Janelle Monáe has finally confirmed rumours of her sexuality, revealing that she does indeed identify as a «queer» woman, as her new album «Dirty Computer» suggests. (contactmusic.net)
MINI Australia have finally confirmed rumours about the local release of the John Cooper Works WC50. (ausmotive.com)
Kotaku were unable confirm the rumours with Bethesda, with minimal staff currently in the office due to summer holidays. (trade-media.com.au)