British actor Benedict Cumberbatch brought in police after he was targeted by an obsessed fan, according to reports.
Red ribbons were tied to the Sherlock star's car and a window at the North London home he shares with his wife Sophie and baby son Christopher, editors at the U.K.'s Sunday Mirror report.
The stunt is believed to be a reference to one of Arthur Conan Doyle's Sherlock Holmes novels, in which the super-sleuth declares, "There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, isolate it, and expose every inch of it."
Editors of the publication report that Cumberbatch contacted the authorities, and Metropolitan Police officers subsequently issued the fan with an official Police Information Notice, which forbids her from contacting the star.
"There was no choice but to pursue official action," a source tells the publication. "Turning up at professional events is one thing, but arriving uninvited at the family home is quite another."
Cumberbatch has also reportedly stepped up security while he performs in Hamlet at the Barbican in London.
His Sherlock co-star Martin Freeman has also been the target of threats since taking part in the TV series - his actress partner Amanda Abbington recently revealed they couple had contacted police over a series of nasty messages which were posted online.
Cumberbatch and Freeman will return in a one-off special of Sherlock, titled The Abominable Bride, which will air in the U.K. on 1 January (16). Filming for the fourth series of the drama series is slated to begin next spring.