Gareth Williams profile: Maths genius with a solitary lifestyle

Gareth Williams crammed his life with secrets – in and out of work.

The 31-year-old excelled as a spy, producing “world-class” code-breaking intelligence for MI6 and the eavesdropping station GCHQ.

Colleagues, friends, family and police queued up to pay tribute to his extraordinary ability, which saw him land a first-class mathematics degree aged 17.

But the teetotal fitness enthusiast lived a solitary personal life that was dramatically removed from the world of espionage.

Police, who painstakingly pieced together his unlikely interests, discovered a fiercely private bachelor fascinated by women’s clothes and drag-queen culture.

He enrolled on a fashion course and collected £20,000 of unworn designer women’s clothing at his pristine flat, including 26 pairs of designer women’s shoes. Small and medium-sized dresses were hung up in his wardrobes, along with women’s wigs, including one Mr Williams had bought on a recent trip to Las Vegas.

Internet searches by Mr Williams and a video taken on his Apple iPhone suggested he wore the shoes.

The flamboyant interests were a far cry from the rigid discipline of work, where he was fast-tracked through the ranks at GCHQ before arriving at MI6 on secondment.

Stephen Gale, his boss at GCHQ’s Cheltenham base, said Mr Williams stunned fellow intelligence specialists with his code-breaking talents when he landed his first job at 21.

He cycled around the Gloucestershire hills “like a red bullet” but won the respect of his colleagues for his “warm smile” and sense of humour under pressure, Mr Gale said. Bosses were so impressed that they paid for him to gain further qualifications in advanced mathematics at Cambridge University.

Mr Williams had won two awards at GCHQ, one for a “Herculean effort” in his top-secret work, Mr Gale added.

But the keen cyclist and fell runner missed the countryside after arriving in London.

Sister Ceri Subbe said: “He disliked office culture, post-work drinks, flash car competitions and the rat race. He even spoke of friction in the office.”

Ms Subbe said her brother was immensely close with his family, from Anglesey.

“In terms of a big brother figure, Gareth was perfect,” she said.

“It’s impossible to do justice to Gareth’s impressive character without meeting him.”

Mr Williams and Ms Subbe “had a truly magical time” during their last meeting for “dainty finger sandwiches” at the Ritz hotel, she said.