ALGONQUIN – Rescue workers from around the region spent much of Friday searching the Fox River in Algonquin for a man who witnesses said jumped in the night before, but the day ended with more questions than answers.

The Algonquin Police Department and several McHenry, Kane and Lake County fire departments suspended an extensive search Friday evening for the unidentified man whom witnesses said jumped into the Fox River late Thursday evening after failing to pay his tab at a nearby restaurant.

Crews searched the area near the dam Thursday night in downtown Algonquin and returned to continue the search Friday until shortly before

6 p.m. The man had not been located as of Friday evening.

After getting multiple leads about the identity of the man, one of the tips appeared to be valid and was being investigated, Algonquin Police Chief John Bucci said.

“At this time, we are not releasing anything further until this information is proven to be accurate,” police said in a news release. “The investigation is ongoing and we will notify the public as more information becomes available.”

A water rescue team from the Algonquin-Lake in the Hills Fire Protection District combed through the water at the base of the dam. A crew using side-scan sonar also could be seen Friday afternoon going back and forth across the dam. Throughout the day, onlookers gathered around the search area to watch.

Friday morning, Bucci said the mission was to search for and identify the man who was spotted jumping into the Fox River by several night anglers. He also said other witnesses saw the man go over the dam.

“We weren’t even on the scene yet when the subject was seen jumping in, so police never had any contact with him,” Officer Jeffrey Diamond said.

The search began after Algonquin police were called about 9:20 p.m. Thursday to Nero’s Pizza and Pub, 300 Eastgate Drive, for a reported theft. The man ran from the scene and jumped in the river after not paying his tab, restaurant employee Tracy Fishleigh said. Fishleigh did not know how much the man owed. Police declined to provide information about the amount of his tab.

Authorities said it was unlikely the man simply ran away because several witnesses said they saw him jump, attempt to cross the river and go over the dam.

The man was described as Middle Eastern or Hispanic, about 6 feet tall, 30 years old and weighing 160 pounds, police said. He was last seen wearing a blue shirt, jean shorts and black shoes.

The Algonquin Police Department posted a photo on their Facebook page Friday afternoon asking the public for any information related to a “well-being check” on the man pictured. The post was taken down hours later with a note that said police no longer needed help to identify the person. It was not clear if the man in Facebook post was the same man thought to have jumped in the river.

• Reporters Hannah Prokop and Jordyn Reiland contributed to this article.