The Environment Agency was first alerted to the oil flowing into the River Aire at Water Lane, Leeds on Saturday August 18.

Mark West of the Environment Agency said: “It’s too soon to be absolutely certain, but we have been working closely with the Police, and have found a very strong lead.

“We’re continuing to investigate and the company involved is co-operating fully. We believe around 5,000 gallons of oil has leaked into the Aire from their oil tank.”

Businesses in the South Leeds area were asked by the Environment Agency to check their oil and fuel tanks for broken pipes or leaks.

The agency said that the company involved may have lost thousands of pounds worth of oil because of the incident.

Mr West added: “What this underlines is the responsibility businesses have to safeguard their fuel tanks under the oils storage regulations.”

Environment Agency staff have been working with the Canal and Rivers Trust and contractors to soak up as much of the oil as possible, using absorbent booms and pads.

However, the huge quantity of oil in the fast-moving waters of the river and canal system means that a large part of it will be flushed downstream into the Humber.

The agency said “By this time it will be very dispersed and the risk to the environment will be greatly reduced”.

Leigh Stringer

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie

Subscribe