Relatives of a London shipping lawyer trapped in the besieged Ukrainian port city of Mariupol have been found alive and escaped their month-long ordeal.

The mother-in-law and two nephews of Mike Lax have managed to get to western Ukraine, where tens of thousands are still believed to be trapped without food water or energy.

Russian attacks on a theatre used as a shelter, and other attacks on schools and hospitals in the city have been labelled war crimes by Ukrainian and Western politicians and campaigners.

“By some miracle, Vera’s mum and nephews were found alive in Mariupol,” Lax said.

TradeWinds reported the text messages to Lax at the start of the war after the Russian invasion that described the harrowing conditions that citizens of the city faced as missiles and bombs destroyed many buildings.

When the messages stopped as the fighting intensified, Lax and his wife feared the worst.

After being found alive, they were evacuated from the city. Galyna, his wife’s mother, was driven to western Ukraine, but was separated from her nephews, Ilya and Zhenya, during the journey.

After travelling by bus via Russian-occupied Berdyansk, the family was finally reunited in Lviv.

Now the two young men face the possibility of being called up into the army and being sent back east to fight.

“[That] seems tough after what they have just been through,” Lax said. “But we have to take one step at a time. Right now, we are just relieved that they are all still alive.”

The United Nations says there have been 3,455 civilian casualties since the war in Ukraine started, which includes more than 1,400 deaths and over 2,000 injured people. The actual number is believed to be considerably higher, the UN said in a recent report.

Lax said: “Vera’s mother can testify that there are dozens of unburied civilian bodies of all ages lining the streets.”

Lax has long experience dealing with Russians in law, having set up his own firm Lax & Co in 2007, partly so he could commit to defending private Russian shipowner Yuri Nikitin in the mammoth High Court fraud trial in London involving Russian state shipping company Sovcomflot.

He now works as a dispute resolution and litigation consultant for Rosling King after the two firms merged last year.

He remains angry at the West for not supporting Ukraine with more military force against Vladimir Putin’s forces for fear of escalating the situation.

“We must stop treating this madman as if he were some logical tactician rather than a liar, gangster and chancer. We must just do what’s right!” he said.