BOSSES of Bioganix, the experimental waste-into-fertiliser project, claimed this week they had made a breakthrough on odour control as Leo minster Town Council called for the plant's closure.

The council was lodging a formal complaint with DEFRA over "sickening" smells.

Councillors at a meeting on Monday also decided to complain to directors of the controversial composting enterprise and to Sun Valley.

Feathers from the poultry processing plant are a major component of the waste handled at the Wharton Court site, near the A49.

Town councillor Derek Eley appealed for action on behalf of "long suffering" residents.

"I drove down the A49 two days ago and the smell was quite sickening, even though the car windows were closed," he said.

A recently-fitted odour filter at the plant was expected to become fully effective by the end of February, said Coun Eley, who expressed doubts that smells could be banished.

Odours escaped when doors of the main building were opened and when trucks were removed and washed down, he claimed.

The end product, the fertiliser, remained "a highly persistent and pungent concoction" when spread on the land, said Coun Eley.

Mayor Janet Atkinson said: "This plant is supposed to be eco-friendly, but it's got to be friendly to everyone. I do not know how the people in the area cope.

"The smells are absolutely nauseating - they make you physically sick."

Nick Helme, of Bioganix, said a bio filter fitted in November had led to a breakthrough in odour control.

Tests carried out this week by the Silsoe Research Institute proved there had been a very dramatic drop in smells and the two-year-old experimental plant was now making good progress.

"We are very pleased," said Mr Helme. "If we had at the beginning what we have now, I don't think we would have had any complaints."

Last year, the town council opposed an application for retrospective planning permission for Bioganix. The planning issue has yet to be resolved by the county council.