A member of the family of 12 feared to have travelled to Syria was stopped by police the day before they left, it has been claimed.

A 21-year-old woman was spoken to at Heathrow Airport on April 9 but was not arrested, before officers searched a property linked to the group, according to the BBC.

Muhammed Abdul Mannan, 75, and his wife Minera Khatun, 53, are missing, along with their 21-year-old daughter Rajia Khanom, 21, and sons Mohammed Zayd Hussain, 25, Mohammed Toufique Hussain, 19, Mohammed Abil Kashem Saker, 31, and Mohammed Saleh Hussain, 26.

Three unnamed children aged between one and 11 - a son of the older couple and two grandchildren - are with the group, as are Mohammed Abil Kashem Saker's wife Sheida Khanam, 27, and Mohammed Saleh Hussain's wife Roshanara Begum, 24.

Police have launched an investigation after the group from Luton failed to return from a holiday in Bangladesh.

Mr Mannan's son Mohammed Akhtar Hussain, who reported the family missing, told Channel 4 News his sister Ms Khanom was initially prevented from flying when she was pulled aside at the airport.

"She didn't have any of her own luggage to check in because everyone's luggage was mixed in together," Mr Hussain told Channel 4 News.

"But the officers thought this was odd as she was supposed to just be going on holiday."

He is adamant his father would not have wanted to go to a war zone.

"I've been worried sick about my father, he's not in the best of health," he said.

The party initially travelled to Bangladesh from Heathrow via Istanbul on April 10, before flying back to the Turkish city on May 11.

They were due to come back to London three days later but failed to return and were reported missing by a relative on May 17.

Bedfordshire Police and Crime Commissioner Olly Martins said police were in "a very fraught and difficult area" when dealing with individuals that might travel to Syria, telling BBC Radio 4's World at One: "As we've seen, they may have grounds for stopping someone but ultimately they were allowed to travel and events have developed in the way that we've seen."

Mr Martins said the priority should be "safeguarding vulnerable people" who might be drawn into support for organisations like Islamic State.

"I think we need properly resourced community policing working with the local authorities, health service and schools, and most importantly working with the community," he said.

"It is often vulnerable people that are drawn into supporting organisations like Isis and it's important really to get an early intervention and a preventative approach going. That requires that the community has confidence in the authorities and that there is a close working relationship, so that when people see people's behaviour changing and early signs of radicalisation, they've got the confidence to prevent these issues.

"It's more about safeguarding vulnerable people rather than trying to criminalise them."