WALNUT CREEK — Police and the Contra Costa Times are investigating how a newspaper hold list ended up in the hands of suspected burglars who used it to target homes while families were on vacation.

The list was recovered in Livermore earlier this month inside a car stolen from a Walnut Creek home. It included addresses of subscribers who had requested the temporary suspension of newspaper delivery while they were out of town on vacation.

The Walnut Creek home was included on the list. Two men were arrested in Livermore in connection with the incident, and police say they were outside a second home they intended to burglarize.

The time frame covered on the vacation-hold list recovered in the car is unclear, and it is unclear how many homes on the list were possibly targeted by burglars.

The recovered list is the first time police have been able to firmly connect burglarized homes with Times’ vacation-hold lists, but police are investigating whether thieves have been using the internal lists to target homes for as long as three months, said Lt. Steve Gorski of the Walnut Creek Police Department.

Investigators are working to determine how the list got into the wrong hands. The newspaper also has started an internal investigation, said David Rounds, vice president of circulation for the Bay Area News Group.

“We want to find out what happened,” Rounds said.

Rounds added that changes to the company’s internal system have been made so that delivery lists do not state whether subscribers have temporarily stopped delivery service or if they are on vacation. Lists will only state that a subscriber has asked to stop delivery and distributors will be notified of resumed service the day of. Gorski said the two men arrested in Livermore were not employees of or contractors for the newspaper. The men were arrested about a week ago, he said. They were driving the car stolen in Walnut Creek when they tried to steal a second car that was idling in a driveway next door to the Livermore home they intended to burglarize, Gorski said. Livermore police were called and arrested the men.

Police did not release the names of the men, and Gorski said they are still looking for at least one other suspect.

Details on the Walnut Creek theft were not available.

Rounds, however, disputed that the home in Livermore was on the vacation hold list, saying police had informed the company that only Walnut Creek addresses were involved.

While the Bay Area News Group publishes many papers, police believe only subscribers to the Contra Costa Times were affected. Anyone with information about the incidents may contact Walnut Creek police at 925-943-5844.

Vacation hold lists have been used to target subscribers before.

The Los Angeles Times announced Jan. 30 that four men were arrested and that police were seeking a fifth suspect for burglarizing homes after the men obtained lists of subscribers who had submitted vacation holds from a vendor that distributed the newspaper.

At least 25 people were burglarized and more than $1 million in property was stolen.

The Associated Press contributed to this report. Contact Katie Nelson at 925-945-4780 or follow her at Twitter.com/katienelson210.