The Hawke's Bay District Health Board will give their evidence at today's hearing into the contamination of Havelock North's water.

The inquiry has reached the end of its first week.

The inquiry panel was told yesterday that the e-coli, which struck down nearly 6000 people with campylobacter last August, came from sheep grazing near the Mangateretere Stream.

It is crucial evidence which proves the source of the contamination, which hasn't been confirmed until now.

The hearing is expected to last until the middle of next week, and the panel will deliver their findings by the end of March.

MORE: Havelock North water contamination inquiry finds cause