The grandfather of two children abducted from their Portsmouth home says the family fear they may never see them again.
Steve Grant said a High Court judge’s decision to allow Usama Al Barwani out of jail was ‘a bombshell’.
Al Barwani, 36, has been released after serving half of a four-year jail term imposed following criminal proceedings.
His former partner - Lacey Plato, 33, from Portsmouth - argued that he was also in breach of a civil court order telling him to return daughter Aishah, 11, and son Faris, eight.
Mr Justice Hayden said jailing Al Barwani had not resulted in the children - who are thought to be with Al Barwani’s sister in Oman - being returned.
He has imposed a 12-month suspended prison term and ordered Al Barwani to arrange to get the children back.
Mr Grant said: ‘We’re disappointed at the outcome. The judge heard that his father refuses to allow the children back, but he is in Dubai and the children are with Usama’s mother and sister in Oman.
‘They could simply be taken to the British Embassy there to be retured. We’re worried that He might find a way of losing his electronic tag. If he gets out of the country, we really believe that we won’t see him or the children again.’
At the High Court on Thursday the judge said Al Barwani would be at risk of returning to prison if he did not comply.
He said arrangements would be made to prevent Al Barwani fleeing the country and travelling to Oman.
The judge said Al Barwani would wear a monitoring tag and have to report regularly to police.
He said Al Barwani would also be barred from entering any UK airport or ferry port and barred from boarding any train heading to the continent.
Al Barwani’s brother Ayman and sister-in-law Kelly were at the hearing.
The judge said they, and other family members, should do what they could to get the children back.
Mr Justice Hayden said Al Barwani had taken the children abroad four years ago - their mother had not seen them since.
He said what Al Barwani had done was flagrant, premeditated, calculated, callous and “fundamentally cruel”.
The judge said Al Barwani was “wholly lacking in empathy” for his children.
He said he did not know who was looking after the children or who went to them when they “cried out in the night”.
Last year another judge, overseeing an earlier stage of the litigation, described Al Barwani as “disgraceful”.
Mr Justice Moor had said it was rare that a court was faced with a father who could behave so “wickedly”.
Miss Plato broke down in tears as Mr Justice Hayden outlined his reasons for not sending Al Barwani back to jail.
Al Barwani showed no emotion, and leafed through the Quran throughout much of the hearing.