Manchester United were under mounting pressure from domestic abuse charities on Tuesday night to drop Antony while the Brazil winger is facing assault allegations against a former girlfriend.

Police are investigating claims by Gabriela Cavallin, a DJ and influencer, that she was subjected to a series of attacks by Antony between June last year and May this year, including when she was pregnant.

Antony, 23, released a statement on Instagram on Monday in which he said his relationship with Cavallin had been “tumultuous, with verbal offenses [sic] from both sides” but vehemently denied “any physical aggression” and said he trusted “the ongoing police investigations will reveal the truth about my innocence”.

Brazil reacted to the latest allegations surrounding Antony by dropping him from their squad for their World Cup qualifiers against Bolivia on Saturday and Peru four days later.

United were staying silent on the matter on Tuesday despite widespread calls from charities to take decisive action just weeks after the club faced a fierce public and internal backlash over their handling of the Mason Greenwood controversy.

Women’s Aid warned United that clubs who allow footballers to continue playing after allegations of domestic abuse against them risked sending out a message that the claims are not being taken seriously.

“Domestic abuse is prevalent in our society and all employers, including football clubs, need clear policies and procedures about what to do when allegations are made against an employee,” the organisation said in a statement.

“When the alleged perpetrator is a high-profile footballer, we know from survivors of domestic abuse that has an impact on both football fans and wider society, who see them playing and celebrated on the pitch as a sign that the allegations are not being taken seriously by the club.

“Safeguarding is vital in these cases, to ensure the safety of everyone involved while proceedings are ongoing.”

Greater Manchester Police are investigating claims by Cavallin that she was headbutted and punched by Antony in a Manchester hotel room the day after United’s 2-1 victory over Manchester City on January 14 that resulted in a cut to her head and a breast implant being damaged. They are also looking into claims she was left with a cut finger after trying to protect herself during an alleged attack by Antony at a house on May 8, the day after the winger had played for United in a 1-0 defeat to West Ham in east London.

Sao Paulo Civil Police are investigating a number of separate allegations, including claims by Cavallin that she was attacked by Antony in a moving car while pregnant on holiday in Brazil in June last year.

End Violence Against Women Coalition, a UK organisation made up of 143 specialist women’s support services, warned United on Tuesday that the “world is watching” to see how they respond to the allegations levelled at Antony, who was named in the Champions League squad the club submitted to Uefa on Tuesday.

“We once again call on the Premier League and FA to take meaningful action as it is clear that these are not incidents they can take in isolation, but part of a pattern of behaviour within a culture that enables footballers to perpetrate violence against women with impunity,” said Coalition director Andrea Simon.

Refuge, the largest domestic abuse organisation in the UK, expressed deep concern at the way clubs were responding to accusations of domestic abuse against footballers.

On Tuesday, thousands of Getafe fans turned up to watch Greenwood train with the Spanish club for the first time following his loan move from United on Friday.

In February, charges of attempted rape, assault occasioning actual bodily harm and controlling and coercive behaviour against Greenwood were dropped by the Crown Prosecution Service after key witnesses withdrew and new material came to light. United had been planning to bring Greenwood back into their squad before a huge backlash forced a rethink and the club announced last month that he would leave.

Tracy Blackwell, director of strategic insights and partnerships at Refuge, said: “Refuge is deeply concerned by the number of domestic abuse allegations involving high profile sports figures, such as footballers, that have been emerging in the media over the last few months, and the responses that clubs have had to these.

“Powerful men so often use their status and their wealth to silence women. It is important that the FA, Premier League, and clubs make it clear to their fans, that they do not condone any forms of violence against women and girls.

“Domestic abuse is a crime and should be treated as such. Swift action needs to be taken to adopt a zero-tolerance policy to abuse and address this culture of violence against women and girls within football.”

Rachel Riley, the co-host of Countdown, who said she would stop supporting United if Greenwood played for the club again and was a strident critic of their handling of that case, has called for domestic abuse experts to be involved in United “club processes” in the wake of the Antony allegations.

Riley, who had called for the United chief executive Richard Arnold to resign over his handling of the Greenwood case, also questioned the “due diligence” the club was doing on signings. Antony was bought from Ajax in an £85 million deal last summer.

The Female Fans Against Greenwood’s Return, a group of United fans who had formed in protest at the prospect of the striker’s return, also voiced their concern over the Antony situation.

They said: “The allegations against Antony are horrific and show clubs and football authorities need to step their game up in how they respond to these issues, because they’re going to keep happening. We know clubs are incapable of being objective and acting in the wider best interest in these cases.

“Charities and organisations, which work to support survivors and perpetrators of abuse, need to be central to developing and advising on how to handle these cases and swifter action needs to be taken in cases where those working in football are arrested and charged for crimes of violence and abuse.”