PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - Malaysian Prime Minister Najib Razak is down with E.coli infection after making visits to flood-affected areas in the country.

In its official Twitter account, the Prime Minister's Office posted on Monday that Datuk Seri Najib had received doctor's treatment and would be taking a short break before resuming his duties.

E.coli are a large and diverse group of bacteria and most strains are harmless.

Rajbans Singh, president of the Malaysian Wellness Society, said the prime minister could have been infected after consuming contaminated food or drinks.

Some kinds of E.coli can cause diarrhoea, he said.

The flooding in the north-east killed 21 people. At its height, almost a quarter of a million people had to abandon their homes.

Mr Najib was forced to return early from holiday in Hawaii after he came under fire when he was filmed playing golf with US President Barack Obama last month during the disaster.

Angry flood victims also alleged the government responded slowly, with people in outlying areas stranded without food or drinking water for days. But following dry weather and as waters recede, many people are returning to clean their mud-filled homes.