Naya Rivera's death has been ruled an accident by medical examiners in California.
The actress's body was recovered from Lake Piru in Southern California on Monday after she was reported missing following a boating trip with her four-year-old son on July 8.
A full autopsy has now been performed, with 33-year-old Rivera's death declared an accident. She drowned, the Ventura County Medical Examiner's Office has said.
No traumatic injuries or evidence of disease were found - and there is no indication that alcohol or drugs played a part in Rivera's death, the medical examiner said.
But specimens from the body will be submitted for toxicology testing, they added.
Rivera's family shared a tribute: "We are so grateful for the outpouring of love and prayers for Naya, Josey and our family over the past week," they told Deadline.
"While we grieve the loss of our beautiful legend, we are blessed to honour her everlasting legacy and magnetic spirit. Naya was an amazing talent, but was an even greater person, mother, daughter and sister."
After thanking the rescuers who helped find her body, the family added: "Heaven gained our sassy angel. We kindly request that our privacy be respected during this very difficult time."
Since news of her death was confirmed, tributes have poured in for Rivera, who was best known for playing cheerleader Santana Lopez on TV musical-comedy Glee from 2009-2015.
The show's creators, Ryan Murphy, Ian Brennan and Brad Falchuk, shared their own tribute, and announced plans to establish a college fund for her son Josey Hollis.
In a joint statement, they praised her work on the show and saying she was a "joy to write for, a joy to direct and a joy to be around".
Her portrayal of Santana, an openly LGBT character who proved hugely popular with fans, was described as groundbreaking.
The creators said: "It was one of the first times an openly lesbian, high school relationship was seen on network television and Naya understood what 'Brittana' meant to the many young women who were seeing themselves represented on television for the first time.
"Naya always made sure that Santana's love for Brittany was expressed with dignity, strength and with pure intentions. Naya was always moved by the girls who reached out to her to tell her how much Santana and Brittany's love affected them.
"Naya's obligation to them - and to all of her fans - was obvious. She had the rare combination of humility and endless confidence in her talent."
Gwyneth Paltrow, who is married to Falchuk, had a recurring role on the show and said she is in "utter shock and disbelief".
She shared a clip from Glee of her performing alongside Rivera and described it as a "special moment".