TV star and comedian Alexander Armstrong was seen delving into history records in Shropshire on a hit genealogy show uncovering a story of murder and intrigue.

The 40-year-old, who is best known for appearing in the comedy series Armstrong and Miller, was shown visiting Shropshire Archives in Shrewsbury and Downton Hall in Ludlow on last night’s episode of BBC One’s Who Do You Think You Are?

Alexander was shocked to find a 220-year-old letter sent to his five times great-grandfather Sir Charles Rouse-Boughton by his brother Edward reporting the “wonderful news” that a cousin has died.

After learning about his links to the English landed gentry thanks to Chris Potter at Shropshire Archives, Alexander was then seen travelling to Downton Hall to view documents about a criminal trial.

The death of Sir Theodosius Boughton, Edward and Charles’s first cousin, meant that Edward, who was heavily in debt, would inherit a baronetcy.

But the archives reveal that foul play was suspected and 20-year-old Theodosius’s body was exhumed and examined by several physicians who all suspected he was poisoned.

Alexander said the tale was “better than a Jane Austen novel”. He said: “It’s like a Gothic horror it’s marvellous.”

While at Downton, Alexander read through the reports of the court case and discovered the man found guilty of Theodosius’s murder was in fact his brother-in-law Captain John Donnellan, although the evidence against him was solely circumstantial and he was executed still protesting his innocence.

Searching even further back in his family history following a fascinating trail of ancient documents Alexander found out he had even more titled relatives descended from one of the richest families in Britain and intimately connected to the King.

Alexander’s final stop was at the College of Arms where he learned he was directly descended from William the Conqueror.

By Russell Roberts