Ekaterina Skopina's daughter Anna-Maria was taken in by relatives while she and her husband were held captive by Russia, having served during operations in Mariupol.

After spending nine months in captivity, a period in which she claims she and her husband suffered torture, she was released.

However, she said the relatives, who were sympathetic to Russia, refused to give her daughter back and that she was kept in Russian-occupied territory

"She was in captivity for almost one and a half years," Ms Skopina told The World with Yalda Hakim.

"They [the relative] refused to bring the child. They blocked me on social media and blocked my phone number, so I couldn't call.

"Then they forcibly changed the child's citizenship, through which they took money, as they took guardianship over her."

Ukraine-Russia war latest: At least four dead in daytime missile strike on port city

Anna-Maria, seven, finally returned to Ms Skopina and her husband in May last year, following a mediation process involving Qatari officials.

Ms Skopina was speaking from Doha, where 20 Ukrainian and Russian families, including 37 children, were hosted earlier this month after being reunited.

"We are very grateful to Qatar for helping and participating in negotiations," Ms Skopina said.

Qatar's Ministry of Foreign Affairs said the families were being hosted in Doha as part of an initiative, carried out in partnership with officials from Ukraine and Russia, to provide them with medical and psycho-social support.

"[The initiative] is to provide comprehensive support that not only addresses immediate needs but also lays the groundwork for long-term healing and integration," the ministry said in a statement.

Another of those to visit Doha was Sergei Sinitsky, whose niece and nephew were recently repatriated from a Russian-occupied area of Ukraine following the death of their parents.

"When this situation occurred and the children were left alone, I began to deal with the issue of how to bring them back, how to bring them to me," he said.

"When the full-scale invasion of Ukraine began, the children were in the occupied part of Ukraine, they were in Mariupol.

"When all this started, they moved to the Moscow region and stayed there. There they attended a regular Russian school and life was more or less normal.

"The only thing is, when my sister passed away, the children were with a distant relative. Their life there was not very good.

"For the last six months, the children haven't even attended school, there was no decent food. In my opinion, if they had stayed there, they would have had no future."

Read more from Sky News:
Russian man arrested after two Ukrainians killed in Germany
Russian priest demoted after holding Navalny memorial service

He said the children wanted to return to him, because he was their closest relative.

"The process of returning the children took several months, and they constantly asked when it would finally happen. It was quite difficult," he added.