(CNN) California Democratic Rep. Ted Lieu said he will donate more than $18,000 in campaign contributions from Ed Buck, a prominent Democratic donor who is being investigated following the second death at his home since the summer of 2017.

The Los Angeles County Sheriff's Department said a man was found dead at Buck's home in West Hollywood, California, early Monday morning.

The man was identified as Timothy Dean, a 55-year-old black male from West Hollywood, according to the Los Angeles County Coroner's office.

In July 2017, a man identified as Gemmel Moore was determined to have fatally overdosed at the same location, authorities said. Buck, 64, was present at the time of both incidents.

Police are conducting an investigation into the more recent death as well as follow-up interviews and a secondary review of the 2017 death to better understand the two cases, authorities said.

Buck has donated to a number of Democratic candidates and PACs, according to information from OpenSecrets , a nonpartisan group that tracks money in US politics.

In a statement, Lieu said he was "deeply disturbed by the latest revelations" of a second death at Buck's home, and said he would donate the funds to LGBTQ and African-American civil rights organizations. Lieu said he will donate $5,000 each to Lambda Legal and the NAACP; $3,000 each to GLAAD and The Trevor Project; and $2,500 to Equality California Institute.

Illinois Rep. Raja Krishnamoorthi, who received $1,000 from Buck in 2017, said his campaign is donating that same amount to a local charity, the Kenneth Young Center, to combat drug addiction.

"I do not have a personal relationship with Mr. Buck. I have not met him, nor has he raised resources from others for my campaigns," Krishnamoorthi said in a statement. "The events surrounding the situation are tragic, and I extend my condolences to those involved and look forward to continuing to work in Congress to provide the resources to help those with addiction challenges."

Two deaths in less than two years

Dean worked at Saks Fifth Avenue's Beverly Hills location and was well-liked in the community, his roommate, Ottavio Taddei, said, according to KTLA

Deputies responded to Buck's home at 1:05 a.m. Monday regarding a person not breathing. They pronounced the man dead when they arrived, the Sheriff's Department said. The cause of death is unknown and will be determined by the Los Angeles County Department of Medical Examiner-Coroner.

The death of Moore, a 26-year-old black man, was determined to be an accidental methamphetamine overdose, the Department of Medical Examiner-Coroner's website says.

The admissible evidence in the case was insufficient to prove beyond a reasonable doubt that Buck was responsible for Moore's death, according to a July 2018 charge evaluation worksheet from the LA County District Attorney. The admissible evidence was also insufficient to prove beyond a reasonable doubt that Buck furnished drugs to Moore or that he possessed drugs, the document states.

The Los Angeles LGBT Center, an organization that provides services and advocates for LGBT people, called on Los Angeles County Sheriff Alex Villanueva to fully investigate the latest death and "aggressively seek justice."

"Although the investigation is in its early stages, we urge Sheriff Villanueva to keep the public fully informed as LGBT people have a considerable and urgent interest in a case that is so clearly linked to the health and safety of our community," the statement said. "The reports we have heard provide more questions than answers."

Buck's attorney, Seymour Amster, told CNN that Buck and the victim had been friends for over 25 years. He said he did not believe there would be charges filed in the case. "Yes, Ed does have individuals he associates with who have problems with drugs. He tries to talk them out of it. Sometimes they bring their problems into his apartment, and that's where the problem is," Amster said.

Political involvement

Buck has contributed to a number of causes and races in California and beyond.

In addition to $2,700 to Lieu, in 2017, he gave $10,400 to the Getting Stuff Done PAC affiliated with Democratic Sen. Kyrsten Sinema of Arizona, and $1,000 each to Rep. Jimmy Gomez of California, Rep. Pete Aguilar of California, Krishnamoorthi and former Sen. Joe Donnelly of Indiana.

He also previously gave $2,700 to Hillary Clinton in 2015, $5,000 to the House Majority PAC that supports Democrats in 2014, and $1,000 to Barack Obama in 2008, according to OpenSecrets.

In 2010, Buck heckled California Republican gubernatorial candidate Meg Whitman at a political event, according to news reports from NJ.com at the time . New Jersey Gov. Chris Christie, who was campaigning for Whitman, then confronted Buck.