Shortly after the reports on Friday, Merrygold posted a picture of himself, Williams, JB Gill and Marvin Humes auditioning for The X Factor in 2008.
He captioned the shot: “These 3 guys... The nicest, most humble, caring, selfless, hardworking (I could go on..) people I’m lucky enough to call family!
“No matter what we are brothers like it or not! And we stand in each other corner.”
Rochelle, who married Humes in 2012, commented “always!!” underneath the post while Alexandra Burke wrote “Amen!!!!!” in the comments section.
Williams has been charged with one count of rape and a second man, Jamien Nagadhana, has been charged with one count of assault by penetration.
A West Midlands Police spokesman said: "Police have charged two men with sexual offences following an allegation of rape at a Wolverhampton hotel in December 2016.
"Oritse Williams, aged 31, from Croydon, London, has been charged with rape.
"Jamien Nagadhana, aged 31, from Hounslow, London, has been charged with assault by penetration."
A statement released at the time of Williams' arrest from his representatives said the singer denied the accusations.
It read: "All we wish to say at this time is that Oritse denies the allegations against him.
"The matter is in the hands of the police and it would be totally wrong for us to comment any further."
Shortly afterwards, the singer said he would be stepping back from his charity work, adding: "Unfortunately, the press speculation is likely to be unhelpful to the charities I work with and the decision I have taken is with their best interests in mind."
Williams and Nagadhana are due to appear at Walsall and Aldridge Magistrates' Court on October 11.
Additional reporting by Press Association.