Hollywood legend Joaquin Phoenix is said to have welcomed a son with partner Rooney Mara.
The pair have reportedly named their son after Joaquin's brother, River Pheonix, who died in 1993 following a drug overdose.
Victor Kossakovsky dropped the bombshell at Zurich Film Festival during a screening for the movie Gunda, in which Joaquin, 45, was executive producer.
Addressing Joaquin's absence from the screening, Kossakovsky said: "He just got a baby, by the way, his name was… a beautiful son called River, so he cannot promote it now."
It's believed that baby River was both a month ago.
Mara, 35, has not addressed her pregnancy but was seen with a blossoming baby bump over the summer.
Joaquin and Rooney who confirmed their engagement back in May 2019 have been isolating at their California home together during the coronavirus outbreak.
The happy couple who met on the set of the 2013 film, Her, are believed to have started dating in 2016 but have kept their lives private.
Since first meeting, they have gone on to star alongside one another in Don't Worry, Dominion, Mary Magdalene and He Won't Get Far On Foor.
Joaquin told Vanity Fair last October that he had initially looked Mara up online.
Speaking about their relationship, he said: "She's the only girl I ever looked up on the internet,
"We were just friends, email friends.
"I'd never done that. Never looked up a girl online."
Since the news broke, fans have taken to Twitter to share the good news and express their happiness for the couple and the tribute to River.
"Finding out Joaquin Phoenix and Rooney Mara have named their son River has made me all emotional," said one.
While a second tweeted: "Congratulations to Joaquin phoenix and Rooney mara on their baby boy! They named him River."
"Congrats to Joaquin and Ronney for the baby! He will be so loved and adored. River Phoenix Jr we welcome you," tweeted a third.
Daily Star Online has approached representatives for Joaquin and Rooney.