A Jewish mother has spoken of her ongoing “hell” in her legal battle to bring two of her sons back to the UK after they were taken to Russia by her ex-husband last year.

Rachael Neustadt, 35, from Hendon, thought that her two elder sons, Daniel and Jonathan, had taken a two-week holiday to visit their Russian-born father’s family.

But, seven months later, Ilya Neustadt, a former London Metropolitan University lecturer, has refused to comply with High Court orders and return the two boys, aged seven and five, to their mother in the UK.

“In the second week of their trip, I started to see problems and wasn’t hearing from them. I then got an email saying he was not coming back,” said Ms Neustadt. “I did not know where they were. It was terrifying. I didn’t think he would do something this drastic.”

The father, 36, later permitted “sporadic” contact via Skype, but after one month, the first conversation “was surreal. To look through a computer and see your own children look back at you — there are no words.

Both of them sat on my lap and didn’t let go. They held me. Having to leave that apartment was hell. - Rachael Neustadt

“They said very little. It’s very confusing for them. I have spoken to them on Skype since then and see changes in their behaviour. They don’t speak English any more — only Russian. It is so unjust — to be kept away from people who love them. It can have a very emotional impact on their lives.”

The couple married in 2004. She described the relationship as “difficult”, and they divorced last spring. She has since made three trips to Moscow, but said Mr Neustadt allowed her only brief contact on her first two visits.

“The first time, I was there for one week, but he only let me see them for two hours. Both of them sat on my lap and didn’t let go. They held me. Having to leave that apartment was hell.”

The couple moved to the UK two-and-a-half years ago, and the children attended the Orthodox Jewish Nancy Reuben primary school in Hendon. She described her youngest son, Meir, 19-months-old, as “my strength. He’s my little mensch”.

Texas-born Ms Neustadt, a former teacher who is shomer Shabbat, added: “I have a rule not to cry in front of them. It’s my job to stay strong.”

Ms Neustadt and her legal representatives at London law firm Dawson Cornwell hope that a Russian court will intervene. A spokesperson for the firm said: “The children have been wrongfully retained (abducted) in Russia by their father. Ilya… also recently told Rachael: ‘I am mother and I am father!’”