China dismissed a rumour on Thursday that bananas grown on a southern island might contain viruses similar to SARS.

"It is purely a rumour and it is impossible for bananas to contain SARS-like viruses," the Agriculture Ministry said, referring to text messages some cell phone users had received.

"The spreaders of the false information either have inadequate relevant scientific knowledge or have ulterior motives," it said, adding police had been asked to investigate.

The rumour about bananas from the sub-tropical island of Hainan had no scientific support as there had never been a case of humans contracting viruses from plants, the Agriculture Ministry said in a statement on its Web site (www.agri.gov.cn).

Hainan bananas were subject to rumours they caused cancer earlier this year when the island's plantations suffered a fungus blight called yellow wilt or, coincidentally, Panama disease.