Reportedly arrested at his UBS trading desk on Thursday, rogue trader Kweku Adoboli is said to have told the bank about his unauthorized trading that resulted in a nearly $2 billion loss before it was aware.

According to the BBC, Adoboli allegedly told UBS about his activity after the bank's monitoring systems had not picked up the loss. He was later arrested at his desk at UBS after the bank contacted London police.

Last week, Adoboli had posted a Facebook message saying, "I need a miracle."

The loss rocked UBS shares on Thursday, wiping billions from trading values, as the Swiss-based company with global operations said it may not show a third quarter profit because of Adoboli's unauthorized trading and losses.

Colleagues at UBS AG called Adoboli, 31, "up and coming" and someone who "worked hard ... played quite hard, too."

Adoboli was arrested on Thursday by London police on suspicion of fraud by abuse of position. Born in Ghana, the Nottingham University alum studied computer science in college and went to work at UBS in London in 2006.

According to the Financial Times, a former colleague of Adoboli's who worked in UBS' London-based exchange and sat near the trader said Adoboli was well regarded by fellow workers.

"He came across as someone who worked quite hard to get where he was and played quite hard, too," the acquaintance told the Financial Times. "There is a lot of shock, horror and disbelief. He was incredibly straight and upstanding with very high integrity. He would definitely not be the first place you start looking."

But over the past month, as global financial markets from the U.S. to Europe rocked among concerns over government debts and slow-growth economies, Adoboli reportedly shared with others concerns through social media posts.

"Can we shut down global markets for a week so everyone can just chill out?" Adoboli wrote in one social network post.

A former landlord said Adoboli is a "well-dressed quiet man" of African origin who wasn't the "tidiest" but was very "well spoken."

Adoboli's father, John, a retired United Nations employee, told the Telegraph from his home in Ghana that his sone made "a mistake or wrongful judgement."

"We are all here reading all the materials and all the things being said about him. The family is heartbroken because this is not our way of life," Adoboli's father said. "I brought them up to be God-fearing and to appreciate decency. Growing up and through to school days they were very brilliant and respectful."

Philip Octave, Adoboli's former landlord, told The Associated Press the UBS employee charged in the rogue trading scheme which rocked the Swiss bank, possibly causing the entire company a third-quarter loss, that Adoboli fell behind in his rent a couple of times but always paid up in the end.

Octave said Adoboli's rent was $6,320 before the investment banker moved out.

"He was not a party chap," Octave told The AP. "I found no problems."

According to a Facebook profile now removed, Adoboli lists UBS as a network, and among "Activities and Interests" lists among many favorites, "Al Jazeera English, Ghana, I'm a Photographer, Not a Terrorist!, Samjhana Moon - Photographer, Wani Olatunde Photography, Brother Mouzone (The Wire), and Vines of Argentina."

Adoboli listed his home as "London, United Kingdom," and has 417 Facebook "Friends," though the number was 420 early Thursday morning. By mid-morning Thursday, Adoboli's Facebook page was deleted.

The Swiss bank's loss "is a staggering demonstration that all the clever systems that the banks now have, especially after the financial crisis, still cannot stop a determined individual getting round them if they want to," Chris Roebuck, visiting professor at Cass Business School in London, told Reuters.

UBS issued a short confessional of the rogue trading loss before European markets opened, explaining to investors that "UBS has discovered a loss due to unauthorized trading by a trader in its investment bank." UBS employees about 18,000 in its investment bank, and most are based outside of Switzerland, working primarily in London and the U.S. Later, the bank told employees it would keep them apprised of the situation.

The bank also sent a letter to employees, attempting to calm shaken nerves about the bank's solvency amid the rogue trading loss.

"Although the news is regrettable, the fundamental strengths of the company won't be affected by this," the note said. "We ask that you continue concentrating on your customers. In these uncertain times they are counting on your support."

UBS says no client positions were affected by unauthorized trading, but the blow will be significant -- and some suggest it could threaten the future of UBS' investment bank, already suffering from reputation blows after massive sub-prime losses during the financial crisis, resulting in government bailout.

UBS suffered an embarrassing U.S. tax evasion case last year that exposed Swiss banking secrecy.