Ananova:

A river in North Wales has been restocked with thousands of fish after a major pollution incident three months ago.

The disaster wiped out 100,000 fish in the River Dee. The cause of the deaths remains a mystery, despite a painstaking investigation by the Environment Agency.

Fishery officials have poured 20,000 roach into Aldford Brook, a small tributary of the Dee, and hope the young fish will make themselves at home before making their way into the main river where they will spawn next year.

Roach, salmon, sea trout, brown trout, pike and barbel, all choked to death when they were starved of oxygen.

Eric Humphreys, from the Welsh Federation of Coarse Anglers, has welcomed the restocking programme, reports liverpool.com.

But he remains pessimistic that the Environment Agency will ever find the cause of the disaster.

The latest theory is that the volume of mud and sediment was so great following severe rain that the oxygen supply was killed off.