Michael Jackson's brother Jermaine has said the singer's child molestation trial has "torn him apart", leaving him unable to make their father's birthday.
Joe Jackson hosted a party at Berlin's Estrel Hotel
Jermaine was in Berlin with other family members for a weekend party to celebrate father Joe's 76th birthday.
Michael Jackson posted a notice on his website last week telling fans he would not be going to the celebrations.
"His case tore him apart mentally. He's very strong mentally, but he needs his rest right now," Jermaine Jackson said.
The statement on Michael Jackson's website also said: "Michael would like to wish his father a very heartfelt 'Happy Birthday' and he hopes that everyone attending the event has a truly wonderful time."
Meanwhile his sisters Janet and La Toya Jackson travelled to Berlin to be with their father.
Hundreds of fans, many dressed as Michael Jackson, flocked to the Estrel hotel to join in the party.
Many said they had also flown to the US to support the singer during the 14-week trial earlier this year.
Jackson, 46, was acquitted of all child molestation charges against him.
He has not been seen in public since he left the Santa Maria courtroom following the acquittal.
He suffered health problems during the trial and appeared increasingly frail.