CALCUTTA, INDIA, June 30. - A new outbreak of cholera has struck the West Bengal district of Bongaon, 60 miles northeast of Calcutta, with more than 500 new cases yesterday alone, a British doctor said today.

Dr. Stewart Clarke, representing the British relief organization War on Want, said that 350 new cases had been reported yesterday, mainly among refugees from East Pakistan.

There has been a large-scale influx of refugees in Bongaon; the refugees are pouring across the border at the rate of as many as 90,000 a day in the wake of the Pakistani Army's effort to crush the Bengali separatist movement.

A British relief team was sent to the area yesterday at the request of the West Bengal state deputy director of public health.

"The hospital at Bongaon is coping at the moment but the number of cholera victims is doubling every day," said Dr. Clarke, who headed all inoculation team in the area yesterday .

Medical authorities said cholera appeared to have been controlled elsewhere.