A Vietnamese woman is feared to be among 39 migrants found dead in a refrigerated lorry in Essex earlier this week.

Though the victims were initially suspected to be Chinese nationals, the family of Pham Tra My, 26, told the BBC they had paid £30,000 for her to be smuggled to Britain but have not been able to contact her since she sent a text on Tuesday night saying she was suffocating.

On Friday the Vietnamese Embassy in London confirmed it has contacted police in regard to a missing woman feared to be one of the 39 people found on Wednesday.

A spokesman for the embassy said they had been contacted by a family in Vietnam which claimed their daughter had been missing “since the lorry was found”.

She has also been named as one of the possible victims by a member of a Hanoi-based human rights group. 

The 26-year-old was identified on Twitter by Human Rights Space coordinator Hoa Nghiem, who said she had sent a series of increasingly desperate messages to her family before she ceased contact. 

“I’m sorry Mom. My path to abroad doesn’t succeed. Mom, I love you so much! I’m dying bcoz I can’t breath … I’m from Nghen, Can Loc, Ha Tinh, Vietnam … I am sorry, Mom,” the message said according to Hoa.

She said Tra My had gone to China and was planning to reach England via France.

“Our contact is getting more alerts that there could be more Vietnamese people in the truck,” Hoa said on Twitter.

The BBC said the families of two other Vietnamese people – a 26-year-old man and a 19-year-old woman – had contacted the broadcaster, fearing their relatives might have been in the container.

Three people were arrested on Friday on suspicion of 39 counts of manslaughter and people trafficking. A man and a woman are both aged 38 and are from Warrington, Cheshire, while a 48-year-old man from Northern Ireland was detained at Stansted Airport.

On Wednesday, the driver of the truck – named locally as 25-year-old Mo Robinson, from Northern Ireland – was arrested on suspicion of murder.