PERTH, England, Sept. 13 (UPI) -- The family of David Haines, a British humanitarian worker held hostage by the Islamic State, asked for his captors to reply to messages they have sent.
Haines, 44, of Perth, was kidnapped in March 2013 while delivering aid in Syria with French agency Acted.
His image recently appeared at the end of a video depicting the execution of U.S. journalist Steven Sotloff. IS -- also known as ISIS and ISIL -- threatened to kill Haines unless airstrikes by the United States and Iraq were halted.
Haines' family this week released a message to IS militants through the British Foreign Office.
"We have sent messages to you to which we have not received a reply," the message said. "We are asking those holding David to make contact with us."
Counter-terrorism expert Will Geddes told BBC Radio 5 the direct appeal could be an attempt to get the militants "to see the human, humanity of the hostage that they've got."
"The second thing could be the lack or breakdown of communications, bearing in mind that there could be any number of links in the chain in any number of discussions."
"To do a public statement by the family is one way certainly to get that message to them very, very quickly," Geddes added.
