Grape juice that sickened 40 people during a church communion service was tainted, prompting authorities to launch a criminal investigation, police said Thursday.

No one was seriously injured after drinking the liquid Sunday, but five people were taken to hospitals with nausea and parishioners reported a burning sensation in their throats.

"Somebody placed this substance into the grape juice," Capt. Fred Komm said. "We are considering this a crime and investigating it as such."

Komm said authorities had not conclusively identified the substance but had ruled out arsenic and other common poisons.

The parishioners became sick after drinking the juice Sunday at Calvary Baptist Church in Darien. Pastor Anthony Gibson said the juice tasted like soap.

"It tasted like drinking straight detergent," Gibson said. "It had no grape juice taste at all."

In Maine three years ago, one church member died and 15 others became ill after drinking coffee that was spiked with arsenic at Gustaf Adolph Lutheran Church in New Sweden. Longtime church member Daniel Bondeson was linked to the poisonings after he killed himself, but the case remains open.