Who Do You Think You Are? (BBC1, 8pm)

AMANDA Holden takes part in the popular genealogy documentary, in which famous faces trace their family trees. The actress and presenter looks into the rumoured French ancestry on her mother's side of the family, an investigation that leads to an extraordinary Napoleonic-era cross-Channel romance. But she doesn't stop there. The suicide of her paternal grandfather has always loomed large over her family – and when his story takes her to France once again, she is moved to discover how he helped others through a harrowing tragedy.

The fact that there are a lot of men in the family tree called Louis and the story that Holden's five-times great-grandfather Collin Thomas, a cordwainer, allegedly married a woman in Bordeaux all fuel the hunt for clues in France.

"I knew we were French," she exclaims at one point. "And from a wine region... and we made shoes. This is going really well. My family history is shoes and wine."

Some find Holden hard going, and Radio Times reveals that, thankfully, there are squeals of delight but no tears.

While investigating the life of her male nurse grandfather, who killed himself in 1983, she unexpectedly finds herself returning to France,

Close to the Enemy (BBC2, 9pm)

KATHY and Callum successfully prevent a war criminal from leaving the country, but suspect he may be too important to prosecute. Callum is instructed to get rid of all information pertaining to individuals of interest, while also having to court the imperious Frau Bellinghausen – who holds the key to an infamous perfume. While all this is going on, Callum's relationship with Rachel intensifies, and Victor and Kathy spot an opportunity to find whatever his department has been hiding. Callum eventually realises he isn't the free agent he believed himself to be, and his dealings inside the hotel bring him closer to Harold, an ex-Foreign Office official, who reveals some startling truths about the outbreak of the war. Meanwhile, word gets out that Dieter may have stood by as innocents in labour camps perished under the rule of the Nazis. Creator Stephen Poliakoff features Know Your Enemy: Stephen Poliakoff in Conversation on BBC2 at 11.15pm.

His latest work explores the clandestine work of the secret service after the end of the Second World War. Historian and broadcaster David Reynolds talks to Poliakoff about the inspiration behind Close to the Enemy, as well as the always tricky relationship between history and fiction.

The Sikhs of Smethwick (BBC4, 9pm)

FILM-MAKER Billy Dosanjh draws on rare archive footage and personal testimony to celebrate 50 years of the Sikh community in his hometown of Smethwick in the West Midlands. It's a story that begins in the late 1950s, when many Sikhs left rural North India to start a new life working in the steel factories of the Black Country. Billy hears stories of the hostility and tough working conditions many of the new arrivals faced, but also looks at the way they have kept in touch with their roots even as their traditions and customs have evolved.

Jack Taylor: In Purgatory (C5, 9pm)

RECOVERING from the mental and physical wounds inflicted from his recent past, Jack (Iain Glen) seems to have found a modicum of peace and has managed to kick the myriad substances that have had a stranglehold over his life. However, this fragile existence is threatened when a vigilante killer begins targeting the scum of Galway, signing cryptic notes to Jack with the moniker C 33. As he tries to work out who this demented killer is, Jack and Darragh are also hired by the billionaire head of a major software company to find out who has stolen valuable games data. With the help of his friends, former dealer-turned-zen master Stewart and dogged police sergeant Ridge, Jack is determined to track down C 33, even if it jeopardises his livelihood, his friends, and what remains of his sanity.

Viv Hardwick