Bay of Plenty Regional Council have announced a diesel oil spill in Tauranga Harbour yesterday has dissipated.

The "small oil sheen" dissipated while Pollution Prevention staff were assessing the situation.

There have been no further signs of a continued discharge.

Council believed it may have been a flush event from a storm drain and no clean up action was required.

The Council reported earlier a minor diesel spill at the Tauranga Bridge Marina. The spill was spread over an area about 6m.

Pollution Prevention staff were on site to assess the situation and officers are currently investigating the source of the spill.