London - England forward Billy Vunipola has been "formally warned" about his future behaviour by his club Saracens who said he made a "serious error of judgement" in defending Israel Folau's anti-gay social media rant.

Vunipola liked Folau's post and called for people to "live their lives how God intended" after the controversial Australia back, who is now facing the sack, claimed "Hell awaits" gay people.

"The player has been formally warned about his future conduct," said Saracens in a statement on Monday after "lengthy discussions" between Vunipola and club representatives.

"At Saracens, we are one family, open to all, with the firm view that everyone should be treated equally with respect and humility," the statement added.

"We recognise the complexity of different belief systems and understand Billy's intention was to express the word of God rather than cause offence.

"However, he made a serious error of judgement in publicly sharing his opinion, which is inconsistent with the values of the club and contravenes his contractual obligations."

The England No 8 simultaneously issued a statement, saying: "I can see that my recent post has hurt people. My intention was never to cause suffering.

"My intention was to express my belief in the word of God. These beliefs are a source of great strength, comfort and guidance in my life," Vunipola said.

"Anyone who knows me, knows I live with kindness and love towards ALL people."

It may not be the end of the matter for Vunipola, who was booed during Saracens' defeat to Bristol at the weekend. The Rugby Football Union said it intends to hold a meeting with the player this week.

On Monday, Rugby Australia gave Folau, Super Rugby's record try-scorer, 48 hours to respond to a code of conduct breach notice over his comments or be fired.

Folau, who was involved in a similar controversy last year, posted a banner on Instagram last week saying: