Update, 11pm. State Highway 25 is now open again, following a serious crash earlier.

Emergency services responded to a crash involving a motorcycle and a van on SH26 Waihi Whangamata Road at around 4.15pm.

One person was transported to hospital in a critical condition.

Diversions were in place while the Serious Crash Unit conducted a scene examination.

The road has now reopened.

Update, 6.20pm Due to a serious crash State Highway 25 is closed between Golden Valley Rd and Gladestone Rd.

"At around 4.15pm emergency services responded to a crash involving a motorcycle and a van on SH25 Waihi Whangamata Road," says a police spokesperson.

"One person was transported to hospital in a critical condition.

"Diversions are in place while the Serious Crash Unit conducts a scene examination. Enquiries to determine the circumstances of the crash are ongoing."

"Please delay your journey or use an alternative route," says a Waka Kotahi NZTA spokesperson.

For an alternative route:

Northbound traffic: Right onto Gladstone Rd, left onto Sommerset St, right onto Surrford St, left onto Barry Rd and Golden Valley Rd, right onto SH25.

Southbound traffic: Left onto Golden Valley Rd to Barry Rd, left onto SH25.

Earlier, 5.10pm Emergency services are responding to a vehicle crash on State Highway 25 between Whangamata and Waihi.

Waka Kotahi NZTA says SH25 is closed between Golden Valley Rd and Gladestone Rd following the crash.

"Please delay your journey or use an alternative route," says an NZTA spokesperson. "Follow directions of emergency service onsite."

It is unknown at this stage if there are any injuries.

The road will be closed until further notice.

SunLive will update this as soon as more information is available.

At the scene? Phone 0800SUNLIVE or email [email protected]