A fresh European arrest warrant has been received by Mr Assange's lawyer - as anger grows in the US over the latest leaked embassy cables by the whistleblowing website.
Sky sources have said officers from Scotland Yard detained the 39-year-old Australian at around 9.30am.
Labelling the move as a "political stunt", Mr Assange's solicitor Mark Stephens said his client wants to find out what allegations he faces so he can clear his name.
Two women in Sweden have claimed they were sexually attacked when Mr Assange visited the country in August. He denies the claims.
Sky News' Rhiannon Mills said: "Authorities in the UK are involved because it is believed Julian Assange has been living in the south east of England.
"They are now obliged to detain or arrest him."
အသက္၃၉ႏွစ္အရြယ္ ဩစေတးလ်ားလူမ်ိဳး ဂ်ာနယ္လစ္စ္နဲ႕ ကြန္ပ်ဴတာပရိုဂဏ္ကြၽမ္းက်င္သူ ဝီကီလိခ္စ္ကိုစတင္သူ ဂ်ဴလီယံ အစန္ဂ်င္ကို၊ ဆြီဒစ္ရွ္ အမ်ိဳးသမီးႏွစ္ဦးကို sexual assault က်ဴးလြန္မႈဆိုတဲ့စြတ္စြဲခ်က္နဲ႕ ျဗိတိန္ရဲမ်ားကလန္ဒန္ျမိဳ႕မွာ ယေန႕မနက္ ၉နာရီခြဲခန္႕ကဖမ္းဆီးလိုက္ပါတယ္။ ဒီစြတ္စြဲခ်က္ကို မဟုတ္ေၾကာင္း သူကျငင္းဆိုခဲ့ျပီး ေရွ႕ေနနဲ႕ မၾကာခင္မွာေျပာဆိုမယ္လို႕သိရပါတယ္။ ဂ်ဴလီယံ အစန္ဂ်င္ ကိုအေမရိကန္ အစိုးရက လိုခ်င္ေနျပီး သူ႕တိုင္းျပည္ဩစေတးလ် ကျပည္ျပန္ဝင္ခြင့္ကိုလက္မခံေၾကာင္း ေနာက္ဆုံးသတင္းမ်ားအရသိရွိရပါတယ္။
After meeting police, Mr Assange will appear before City of Westminster magistrates so a decision can be made about whether the warrant is appropriate for extradition. But Mills added that Mr Stephens has warned any attempt to extradite will be resisted, "mainly on the grounds that he may be handed over to the Americans".
Sky News' US correspondent Greg Milam said officials in Washington are watching developments "very closely". He added: "There is a growing clamour in the US for something to be done even if they're not completely sure what that should be.
Posted 7 December, 2010 - 11:08 by အဲလ္ဘတ္သန္႕စင္