Beast of Bosnia's secret life: Karadzic had a mistress and drank red wine under a picture of himself in the Madhouse bar

Such was his secret life that the man accused of responsibility for the murder of 20,000 civilians lived as a fugitive in Serbia for more than a decade.

Locals say he practised alternative medicine, visited a bar and saw his girlfriend. Only his beard and hairstyle appeared to mark him out.

Mistress: Radovan Karadzic and his girlfriend Mila, described as 'an attractive brunette in her early 40s'

But following his arrest this week, details of Karadzic's existence as Dr Dragan Dabic emerged.

He had taken the alias from a Bosnian Serb who died during the war in Sarajevo in 1993.

And while Karadzic's wife Ljiljana remained in their family house in the former Serbian stronghold of Pale, east of Sarajevo, he had a girlfriend called Mila.

She was an associate in the alternative medicine business he ran, he told Zoran Pavlovic, a software engineer he hired.

As Dr Dabic, Karadzic worked as a practitioner in alternative medicine and wrote for Serb publications.

He also had his own website, set up by Mr Pavlovic, to advertise his expertise in 'human quantum energy'.

Undercover: Karadzic avoided detection by growing a flamboyant beard

Describing Mila, Mr Pavlovic said: 'She was an attractive brunette in her early forties. He only ever introduced her as Mila.

'She sometimes offered her own suggestions for the website. If anyone knew who he really was, the girlfriend must be the one.'

Yesterday Mila could not be tracked down. Some reports suggested she was in custody.

Karadzic was the architect of the Srebrenica massacre and the siege of Sarajevo in the Balkan wars of the early 1990s, when he was Bosnian Serb president.

He awaits extradition and trial in The Hague.

Last night it was reported Karadzic's arrest may have followed a tip-off by the Hague's other most wanted man, former Bosnian Serb army commander Ratko Mladic.

Favourite haunt: The Madhouse bar in Belgrade, which war crimes suspect Radovan Karadzic frequented

Intelligences sources said Mladic allegedly passed on information about the whereabouts of Karadzic in a bargain to delay his own capture and trial for war crimes.

However, rather than deflecting interest in Mladic,  Karadzic's arrest has served to increased demands for his sidekick to be brought to justice.

Intelligences sources also said British intelligence officers had helped bring about Karadxic's arrest, along with others from the CIA and German and French intelligences serves .

Until this week, those around him said they had no idea about his double identity.

Dr Dabic lived in an apartment in a grim suburb called New Belgrade, Mr Pavlovic said. He often visited a nearby bar called The Madhouse.

He would drink wine in the bar, which is decorated with a photo of himself and fellow war crimes fugitive General Ratko Mladic, said landlord Misko Kovijanic.

A magnet for nationalists who share his view of Serbian glory, the bar was a safe place.

Often, when he had been drinking, Karadzic would reach up from his table near the bar and take from the wall a gusle - a single-stringed musical instrument his father taught him to play.

He would strum it as he sang or narrated epic stories of Serb greatness.

Drinkers said he often chose to perform under a portrait of Mladic.

The landlord says he was fooled about Karadzic's identity - and knew him by his nickname Santa - because of his beard.

'I never recognised him at all. I guess it was a year ago he first visited the restaurant.

'There was a musician playing the gusle and Santa got up and played himself.

'He would come in, oh, two to three times a week. He would start with some hearty red wine, maybe eat a few kebabs and then finish up the sliwowitz .

'He was quiet but of course he attracted a bit of attention because of the way he looked.'

Every other day, Karadzic bought yogurt and bread at a local store, often with Mila, said shopkeeper Gordana Blagojevic.

'He was so nice, and she was a lovely girl too.'

Since October, Karadzic had been writing for the Serbian alternative medicine magazine Healthy Life.

Editor Goran Kojic became suspicious when Karadzic couldn't present a diploma to back his claim of being a therapist.

'He said he had left it with his ex-wife in the States.'

He had told others of his supposed family in the U.S. as well. At his two-bedroom rented flat was a photograph of four boys dressed in LA Lakers T-shirts.

Karadzic told Mr Pavlovic they were grandsons in the U.S.

Karadzic always dressed in black and often complained money was hard to come by, Mr Pavlovic said.

'Frankly, he scared me a bit. I thought he belonged to some religious sect or something, with that beard and all.'