Original Disney Mouseketeer Dennis Day Has Been Missing for 6 Months

Dennis Day, one of the original Disney Mousketeers from the 1950s, has been missing for over six months, police and his family say.

Although Day, 76, has been reported missing from Phoenix, Oregon since July 15. His family did not find out about it until they saw a missing person report on TV in January, NBC News reports.

"He saw it on the news broadcast and called us immediately," Day's sister Nelda Adkins told NBC. "I called Phoenix Police Department the very next day, and we've been working on it ever since. The whole family got in on it."

The July missing persons report was reportedly filed by Day's husband, Ernie Caswell, who suffers from "age-related memory loss."

"Ernie was in the hospital at that time, and he realized Dennis hadn't come to visit him in a few weeks," Adkins told Dateline. "So he had someone from the hospital call the police and report Dennis as missing."

Day's case is being handled by the Phoenix Police Department and the Jackson County Sheriff's Office, according to NBC.

"I initiated the case on July 27, 2018," Lt. Jeff Price from the Phoenix, Oregon police department told PEOPLE this week. "As of today, with the help of the Oregon State Police, Jackson County Sheriff's Office, National Missing and Unidentified Person System, and numerous friends and family, the case remains open with no leads as to Dennis's whereabouts."

Adkins said police didn't contact Day's family, who lives in California, because they had no record of family other than Caswell, who wasn't able to provide contact information because of his dementia.

Police reportedly told Adkins that a man who was living at Day and Caswell's house at the time Day disappeared said that he had left on foot and said he was going to visit some friends.

"Ernie, at the time, was in the hospital, so he wasn't even at the house," Adkins said. "Dennis had a car, but the car was left behind. He left his dog and his cat behind, too – he loved them dearly, just like children."

She said by the time the family finally discovered Day was missing, police told her they had already searched his home, a nearby graveyard and a nearby creek.

"They said they brought in cadaver dogs, too," Adkins added. "But they never found anything that would imply a crime had happened."

Although Day and Caswell's roommate told police Day left on foot, Day's car was found along the Oregon coast shortly after his disappearance. Two people that Day did not know were inside the car, and it's unclear how they gained access to it.

Day's family is calling the investigation "poorly-handled" and said they are trying to pick up the pieces.

"We are devastated. We had no idea anything was happening and six months into it, we figured it out. We should have been notified," Day's niece Denise told Dateline. "We are devastated by the whole thing. We just know someone knows something."

"He's not the type of person who would just disappear. Especially with his significant other being in the hospital – he was very dedicated to him," Denise said. "We are worried. [We] just need answers. We love him. We're just kind of lost with what to do, or how to find him."

According to the Mail Tribune, Day was a Mouseketeer from 1956-57 and a "long-time entertainer and director for the California Renaissance Pleasure Faires & Dickens Fair."

Disney's The Mickey Mouse Club first aired from 1955-1959. The children's variety show was rebooted in 1977 and then again, most famously, from 1989-1994, where future A-list entertainers Britney Spears, Ryan Gosling, Justin Timberlake and Christina Aguilera starred as singing and dancing Mouseketeers.

According to a Facebook page set up to help find him, Day is described as 5'7" with gray and brown hair and weighing approximately 150lbs.

Anyone with information about Day's disappearance is encouraged to call Lt. Jeff Price of the Phoenix Police Department at 541-535-1133, ext. 309, or the anonymous tip line at 1-888-960-6450.