The bottle of Diet Coke that sent a University worker to the hospital last month has tested positive for a foreign substance.

The test, conducted by the Massachusetts State Laboratories, revealed a substance chemically similar to diesel fuel--a finding that is consistent with reports by the employee, who said the bottle of Coke, purchased in Loker Commons, smelled like fuel.

"We did find hydrocarbons indicative of petroleum distillates in the Coke," said Erica Berl, the coordinator of the Food-Born Illness division of the Mass. Department of Health.

The lab also tested three sealed bottles produced at the same time in the Needham bottling plant as the contaminated bottle and did not find anything wrong with them.

Health officials have not been able to determine the source of the contamination.

"We had a similar case of this in the past and it was [machine] lubricants," Berl said. "So one of our inspectors went out to the plant and he brought back a couple of grease samples which didn't match [those found in the contaminated Coke]. He couldn't find anything else wrong at the plant."

Yet despite the discovery of an fuel-like substance, Coca-Cola stands by its own tests, which did not find anything abnormal.

"We got the results back and we were able to determine that there was no problem with the drink," said Robert Lanz, Coca-Cola's vice-president of public affairs.