It was with all the requisite drama The Traitors demands that host Claudia Winkleman announced on Friday night's episode that the prize fund for its eventual winners had reached a 'staggering' £52,000.

Amid the wide eyes and joyful grins, it would not have taken a super sleuth to notice that one of the contestants barely blinked.

To be fair to Harriet Tyce, now favourite to take this year's crown on the hit BBC show, she is not prone to emotional outbursts.

Indeed, as a calm member of the Faithful, her quiet – and yet eerily accurate – analytical skills have proved a crucial tool in helping them nab two Traitors so far.

But there is another reason, perhaps, for her understated demeanour when it comes to the prize pot.

Namely that, for Harriet and her husband, the sum is small change.

Along with a successful career as a barrister–turned–bestselling crime author, The Mail on Sunday can reveal that Harriet, 53, is married to a multi–millionaire City trader – with friends quipping that they're 'absolutely minted'.

Nathaniel Tyce is said to earn around £3.5million a year at Japanese bank Nomura, where he is head of global markets for Europe, the Middle East and Africa. Married to Harriet for 25 years, Nathaniel worked for Barclays for decades before making the switch, and some have suggested they may have already built up a fortune of more than £15million.

That's nearly enough to buy Ardross Castle – the stunning Highland location for The Traitors.

But the couple instead live in a large townhouse on a beautiful tree–lined street in the North London enclave of Highbury, known for its high concentration of so–called 'champagne socialists'.

Traitors contestant Harriet Tyce lives in a large townhouse on a beautiful tree–lined street in the North London enclave of Highbury with her multi–millionaire City trader husband 

Harriet is quickly shaping up to be a Traitor spotter supremo - and is now favourite to take this year's crown on the hit BBC show

And being on the show has certainly not harmed Harriet's coffers. Sales of her crime novels have rocketed 96 per cent since the show launched on January 1.

One friend said: 'Her husband is coining it in but so is Harriet. Traitors pays – look at her sales. She is not a stupid woman.' Indeed not. On Friday night, an impressive 7.9million viewers tuned in to watch as Harriet turned her forensic attention to another of the programme's favourites, communications executive Rachel Duffy, who has been a Traitor since the start.

Her suspicions were And when Fiona was banished and unmasked following the show's Round Table, Harriet pondered to the camera – correctly – that emotions could have run high because both were Traitors, paving the way for what promises to be another tense episode on Wednesday night.