The boss of biotech firm Oxonica is confident of new growth after one of its key products received a major boost.

Dr Kevin Matthews is delighted that its fuel additive Envirox which is designed to improve emissions and cut particulates, has passed an ongoing test with bus operator Stagecoach and will now be adopted across its 7,000-strong UK fleet including its vehicles in Oxford.

The move follows a major setback for the company based at the Begbroke Science Park last year when Envirox failed to live up to expectations in trials with Turkish oil company Petrol Ofisi.

That led to the loss of the Turkish contract, ten redundancies and financial losses spiralling to £3m.

But speaking to the Oxford Mail today, chief executive Dr Matthews said: "The importance of this is to re-establish the credibility of Envirox which is performing as we would have expected.

"We are also seeing positive results across Europe. What we are saying is 'we are back.'"

The most recent Envirox trial on 550 Stagecoach vehicles showed a fuel saving of 4.3 per cent over three months while another trial in Italy revealed a 10.6 per cent improvement over six months. Particulates from diesel fumes have also been cut by up to 19 per cent.

Dr Matthews added that the business had also recently received £4.2m of funding from investors, securing the jobs of its 22 staff in the UK and 28 in the United States.

He said he was now looking for partners to help out with its diagnostics products, reducing the financial burden.

"Our materials division including Envirox is not that far away from breaking even," he added.

"This is a growth business and by all means we will be looking to rebuild the staff."