Thousands owe their lives to secret agent Frank Foley

Frank Foley was based in Berlin in the 1930s, working as a passport control officer, and using his position to provide papers for Jewish people.

It is believed Mr Foley saved tens of thousands of lives, even hiding people in his own home.

Foreign Secretary Jack Straw described him as "a true British hero".

Eyewitnesses recall Mr Foley as an unassuming hero - a small, slightly overweight man with round glasses .

But he was actually Britain's top spy in the city.

He not only interpreted the rules on visas loosely, enabling Jews to escape to Britain and Palestine, but he also helped to forge passports.

And, despite not having diplomatic immunity, he gave shelter to some people in his own home.

Mr Foley's efforts have already been recognised by Israel, which declared him a righteous gentile, like Oskar Schindler, and he has also been honoured by his home town of Stourbridge in the West Midlands.

With Foley a lot of the people he helped probably didn't even know he helped them

Michael Smith, biographer

Michael Smith of the Daily Telegraph, who wrote a book about him, said that although it is not known exactly how many lives Mr Foley saved, archive evidence would suggest the number was in the tens of thousands.

He told BBC Radio 4's Today programme: "With Schindler you had 1,400 people working in a factory, working with him, they worked closely together. Their lives were together.

"So when they moved to Palestine, which later became Israel, they are all talking to each other, they are still on the phone to each other even if they are not living in Israel - they have a collective memory of what Schindler did.

"But with Foley a lot of the people he helped probably didn't even know he helped them.

"They were helped in ones or twos or in small family units - five or six people perhaps. They have got to Palestine. They have a visa they know they shouldn't have - they are not going to talk about it."

Delphine Cook - the niece of Captain Foley's wife - told the same programme that she did not remember him personally but that her father had told her about him.

She said Mr Foley was a "very private person" but that he would have been "pleased that his work had been recognised".