UPDATED 1.36pm: Greymouth police have charged a 30-year-old man with the murder of a 15-month-old boy who was killed almost 10 months ago.

Leith Hutchison was rushed to hospital in cardiac arrest in April.

A bleed of his brain was later identified by medical staff.

Detective Inspector Paul Borrell said they've spent the past 10 months undertaking a comprehensive and intensive criminal investigation which concluded with the arrest.

The man is due to appear in the Christchurch High Court on the 12th of February.

A family spokesperson said the past few months have been harrowing for the family, but they're relieved an arrest has now been made.