Friday’s pollution incident in the River Esk at Musselburgh could lead to enforcement or criminal action.

The Scottish Environment Protection Agency and East Lothian Council are continuing to work together to respond to the spillage, which is believed to be oil, petrol or diesel.

The local authority has arranged for further booms and inspections to be put in place to "contain material, monitor and further protect the environment".

READ MORE: Swan taken to wildlife centre after coming into contact with pollutant 

SEPA officers have been on site monitoring the impact and continuing investigations into the cause.

The council together with its contractor is continuing to assess remediation measures to mitigate the impact.

Close monitoring of wildlife on the river continues, with any distressed birds being taken into care by the Scottish SPCA as space at their National Wildlife Rescue Centre becomes available.

READ MORE: Efforts continue to tackle pollution in River Esk

Given the current national risk of bird flu, it is requested that the public do not touch or handle any birds but instead report these to the Scottish SPCA on 03000 999 999.

With speculation rife, SEPA has been asked by the Courier to disclose the location of the manhole where the pollutant entered the watercourse but it says it is unable to comment further at this stage "given the matter is a live investigation and due to the potential for enforcement or criminal action".

The oily discharge into the river has ceased though not before impacted wildlife including swans.

SEPA has asked anyone with information to contact its 24-hour Pollution Hotline on 0800 80 7060, via sepa.org.uk/report or to contact CrimeStoppers anonymously on 0800 555 111.

In a statement, it said: "This pollution incident has been very concerning for local communities. We are very grateful to local people for their support and understanding during this incident."