A father is fleeing Russian authorities with his two children after defying a second court order to bring them home to Hendon.

Iljavadimovic “Ilya” Neustadt is on the run with sons Daniel-Jakob, eight, and Jonathan, five, and the trio have not been seen or heard from since November 15.

Their mother Rachael Neustadt says she cannot find the words to describe the pain of not knowing the whereabouts of her two oldest children.

The boys, who attended Nancy Reuben Primary School, in Finchley Lane, Hendon, were taken on a two-week holiday to Moscow in December 2012 as part of a custody agreement.

Their parents had divorced in 2011 and after a lengthy court battle Mr Neustadt was given permission to take their sons to see his brother in his native Russia, with his mother as a chaperone.

During the two-week trip, Mrs Neustadt had regular contract with her sons via Skype - but on January 7, the day they were due to return, she received a heartbreaking phone call.

The 36-year-old said: “I was worried about sending them to Russia, I knew I’d miss them, but I couldn’t defy what the courts said. He was calm and told me they were in a hotel, and the children weren’t coming back.

"What do you feel? How would any parent feel to be entirely powerless to rescue their child from harm? It’s like a gnawing feeling at your heart.

“I was frantic, but it’s not a place I like to go back to. I want to focus on the future now, and getting them back."

In time, a Russian court heard how Mr Neustadt had supplied the English authorities with a false address for his brother's house.

Instead of spending the trip with his sons, he had left them with his mother before taking a plane back to England where he quit his job and gave up the tenancy on his flat.

Last September, judges finally ruled that he should return the boys to their mother and dismissed a subsequent appeal from Mr Neustadt in November.

Before the court’s ruling, his former wife made regular trips to see the boys in Russia - but was only permitted to see them for less than an hour on the day she was due to leave.

She said: “They did seem a bit tense, though they were happy to see me. They were dancing and singing ‘mummy is here, mummy is coming back tomorrow’.

“It was heartbreaking, I didn’t know how to tell them I couldn’t.”

The school the boys attended in Russia confirmed they have not attended lessons since November 15, and the authorities have been unable to track the trio down.

Both boys are on the Interpol list but Russian authorities have so far been unable to track the pair down.

Mrs Neustadt, who calls herself a “left-behind mother”, is now pouring all her efforts into finding her children, while caring for the couple’s third son, Meir, now two.

The walls of her flat are littered with paintings and drawings her boys had made when they still lived at home, but now they are just bittersweet reminders of her heartbreaking situation.

It has now been more than 440 days since she has seen her children and since their abduction, she has been forced to become an amateur lawyer, expert in international law and accountant - all in an effort to get her sons back.

The Jewish Aid Committee is now backing her campaign to raise £35,000 to pay the legal fees needed to take her case further.

She said: “I am emotionally broken. The anxiety I feel is indescribable, but I live and breathe for my children. I just want them to come home to me.”

A statement from the British Foreign Office said: “This is a very difficult case and our sympathies are with all those involved. The Foreign and Commonwealth Office has offered the support and advice it is able to in this particular case.”