Planning is underway to recover oil located inside Rena's aft section.

Resolve Salvage & Fire divers have this week located several small pockets of oil trapped inside the engine room and remains of the accommodation block of the MV Rena wreckage.

Divers are planning on how to recover oil found leaking from the Rena this week.This picture was taken after it grounded in 2011.

They are now planning how to recover them at depths between 35 and 48 metres.

Roger King of TMC says the diving operation was purposefully undertaken in response to sheens of oil surfacing during ongoing clean-up operations at the site, which are difficult to recover due to the small and periodic quantities escaping.

'Bay of Plenty Regional Council and Maritime New Zealand representatives have been briefed of the situation including a light sheen on Thursday – both authorities are supportive of the action being taken,” says Roger.

'While the accumulation and gradual release of small quantities of residual oil over time has been expected, the overall quantity that remains is believed to be less than a tonne. We won't know the amount we are dealing with here until the recovery operation is completed.”

Roger adds: 'To have located the source is a positive development – the owner's insurer has now instructed plans for the oils' removal in a safe and responsible manner.

'The depths divers will be working at will require further careful planning, as well as to ensure we have adequate spill response resources in place during the operation.”

In the early hours of October 5, 2011 the Rena ship grounded on Astrolabe Reef about 25km off the coast of Tauranga causing one of the country's biggest environmental disasters.