A 47-year-old man is in a critical condition in the Royal Hobart Hospital after crashing a motorcycle on Paradise Rd, Paradise about 2.35pm yesterday.

The Tasmania Ambulance Service attended the scene and the man was airlifted to the RHH where he is undergoing surgery for his injuries.

Excessive speed is believed to be the major contributing factor for the crash, however, police are unable to discount that alcohol or illicit drugs may have also contributed.

Investigations are continuing and police are asking for any witnesses to a green Kawasaki motorcycle being ridden in the Paradise/Sheffield area around the time of the crash to contact police.

Information can be provided anonymously by calling Crime Stoppers on 1800 333 000 or online at crimestopperstas.com.au