"The notification has arrived and is being translated," tribunal spokesman Refik Hodzic told Hina by telephone on Thursday, adding that Margetic must appear for the sentencing regardless of the notification.
"If he fails to show up, the trial chamber has different measures at its disposal," the spokesman said.
According to Margetic's blog, in the notification the defence cited his health condition and the condition of his common-law wife as reasons why he would not be able to attend the hearing.
On Monday, Margetic was taken in an ambulance to Zagreb's Merkur hospital after feeling unwell. He was discharged the same day, with doctors recommending that he should see a psychiatrist and a neurologist.
Margetic called the ambulance several times after that, but the ambulance refused to respond to his numerous calls, his blog says.
Margetic, 33, was indicted after he published a list of 102 protected witnesses on his web site in the summer of 2006. Prosecutors demanded that he be sentenced to six months in prison and fined 50,000 euro for knowingly violating the tribunal's rules.
The trial chamber ordered him to come to The Hague for the sentencing hearing. Awaiting a judgement, Margetic began a hunger strike last Friday.