A section of track is sinking and cracks are appearing in the platform at Newmarket's new $35 million railway station.

KiwiRail yesterday confirmed a 10 metre to 15 metre section of track at the northern end of the platforms next to a construction site had dropped 15mm. There were also some visible cracks on the platform.

Neither problem was affecting safe rail operations or passenger movement, a KiwiRail spokeswoman said. "We have had structural checks done by independent structural engineers and will continue to monitor the situation throughout the neighbouring construction process," she said.

An Auckland Transport spokeswoman said: "The cracks on the platform area are cosmetic and do not impact on the safety of rail operations. We are monitoring the situation." The new railway station opened in January 2010.