BIODIESEL company D1 Oils has recruited a top agricultural expert to help it produce higher vegetable oil yields from its renewable energy crop.

Teesside-based D1, which produces biodiesel from the jatropha shrub, a South American weed traditionally used as medicine, is trying to maximise the amount of oil it can squeeze from the crop.

Now Dr Sunil Puri, a leading Indian agronomist - or expert in the science of crop production - is to work in D1's labs in India to produce higher-yielding jatropha.

Dr Puri is an expert on jatropha and was recently named a Fellow of India's National Academy of Agricultural Sciences.

He will head research to improve the yields of certain varieties of the crop collected by D1, and identify the varieties that grow best in certain soil and climatic conditions.

India is expected to be a key location for the production and consumption of jatropha biodiesel.

D1 has been signing deals in Asia and Africa to grow hundreds of thousands of hectares of jatropha. The seeds are then crushed to produce vegetable oil, which is mixed with diesel to create biofuels.

At its Teesside headquarters, D1 is developing refineries that can be taken worldwide, to sit next to its jatropha plantations, minimising the mileage the vegetable oil has to travel.