The parents of US student Amanda Knox say they will "reach out" to the family of murder victim Meredith Kercher - but when their daughter has been freed.
Knox is appealing against a conviction for killing Miss Kercher, 21, a Leeds University student from Coulsdon, south London, in their house in Italy.
Her father John Kercher told the Daily Mail "no letter of sympathy; no word of regret" had come from Knox's parents.
But Curt Knox told the BBC they had expressed condolences whenever asked.
"It's unimaginable the pain they must be experiencing but we also believe Amanda is innocent and we are going to do everything we can in our human power to have the truth come out," he told BBC Radio 5 live Breakfast.
"Once that truth comes out and Amanda finally comes home, we will reach out to the Kercher family to try to express our deepest condolences personally."
Together with Knox's mother, Edda Mellas, he expressed hopes their daughter's appeal, launched last month, would be successful. The Kercher family did not respond when approached by the BBC.
The 23-year-old was jailed for 26 years for the 2007 murder along with former boyfriend Raffaele Sollecito, who received a 25-year sentence.
Miss Kercher had been found at the house in Perugia with her throat cut, her semi-naked body partially covered by a duvet in her bedroom.
Their trial heard the pair had cornered Miss Kercher after starting a sex game with Ivorian drug dealer Rudy Guede, who had his 30-year sentence for the killing reduced to 16 on appeal.
Mr Knox and Ms Mellas have persistently argued their daughter's innocence through the media.
And, writing in the Mail earlier this month, Mr Kercher told of his anger at them being given "star billing on the ITV breakfast show Daybreak".
"Kurt Knox and his ex-wife Edda Mellas have never expressed their condolences to our family for our grievous loss," he wrote.
"There has been no letter of sympathy; no word of regret. Instead, I have watched them repeatedly reiterate the mantra of their daughter's innocence."
And he added: "To my family she is, unequivocally, culpable."
But Ms Mellas said: "Any parents, including them, if their child was locked up for a crime they didn't commit... would fight and do everything they can to not leave their child locked up."
Knox's defence team maintains that the DNA evidence in the case was inconclusive and has argued it may have been contaminated when analysed.
The next hearing in the appeal is due to take place on Saturday.
Mr Knox repeated claims that the media had portrayed his daughter in a way he did not recognise and criticised what he saw as over-aggressive interrogation by Italian police.
"We look forward to this wrongful conviction being overturned," he said.
As in the original trial, the appeal verdict will be decided by the judge, a fellow magistrate and six jurors.